If you have a full-size or compact Glock with the traditional MOS cut, you have a lot of red dot options available to you. This guide is specifically for Gen4 and Gen5 Glock MOS slides. It does not apply to the newer Gen6 ORS cut, and it also does not apply to the Glock 43X or 48, which use a different slimline MOS optic cut.
In this article, we’ll go over which Osight optics will fit your Glock MOS slide, which ones can mount directly, and which footprints will require an adapter plate. The goal is to make it easy to figure out exactly what you need before you order anything.
Which Glock models does this apply to?
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Which Osight optics do we recommend for the Glock MOS?
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Why Consider an Osight Red Dot?
Osight has made a name for itself by offering pistol red dots without pushing the price into premium-optic territory. They’ve also been pretty willing to try things that are a little different, with features like rechargeable optics with magnetic charging covers, multiple reticle options, enclosed emitter designs, and newer housing materials like OAL.
For a Glock with the traditional MOS cut, there are quite a few Osight options to choose from. Depending on what you’re looking for, you can go with a smaller carry-oriented optic, a larger-window RMR-style optic, an enclosed emitter, or a rechargeable model.
One of the nicest options is the Osight SE MOS, which is designed to mount directly to compatible Gen4 and Gen5 Glock MOS slides without an adapter plate. That keeps the setup simple, lowers the optic closer to the slide, and saves you the added cost of buying a separate plate.
Overall, Osight gives Glock MOS owners a pretty wide range of choices at approachable price points, so there’s likely an option that makes sense whether your pistol is set up for concealed carry, home defense, range use, or just general shooting.
What Optics Footprint Is the Glock Gen4/Gen5?
If you have one of the Glock models covered in this guide, the factory optic cut is the Glock MOS (Modular Optic System). The Glock MOS system was designed to work with multiple optic footprints by using different adapter plates. This gives you quite a bit of flexibility because you aren't locked into one optic footprint.
What Adapter Plates Exist for the Glock MOS?
One of the biggest advantages of the Glock MOS system is that you’re not locked into a single optic footprint. By using an adapter plate, you can mount a wide range of red dots to the same MOS slide.
Adapter plates are available for popular footprints like RMR, RMSc, and DPP, along with several other mounting patterns. That gives you a lot of flexibility when choosing an optic, especially since many red dots are built around one of these common footprints rather than the MOS cut itself.
The important part is matching the correct plate to both your Glock MOS slide and the footprint of the optic you want to use. Some optics, like the Osight SE MOS, skip this step entirely and mount directly to the MOS cut, but all other Osight models will require the appropriate adapter plate.
To make that easier, we’ll link to our Glock MOS Adapter Plate Finder, where you can see the available plate options and find the one that matches the optic footprint you want to run.
Osight Direct Fit Optic for the Glock MOS
1. Osight SE MOS - Compact RMSc Enclosed Emitter
Buy the Osight SE MOS At The Best Price
The Osight SE MOS is an enclosed-emitter pistol optic designed to mount directly to Glock Gen4 and Gen5 MOS slides. Unlike most pistol optics that require an adapter plate, the SE MOS is built specifically for the Glock MOS system, creating a simpler direct-mount setup.
The optic is available exclusively with a red multi-reticle system featuring a 2 MOA dot and 32 MOA circle. You can switch between the 2 MOA dot with the 32 MOA circle, the 2 MOA dot by itself, or the 32 MOA circle by itself.
Power comes from a side-loading CR1632 battery. Battery life is rated for up to 140,000 hours at brightness setting three while using the dot-only reticle. A motion sensor also helps conserve battery life by activating the optic when movement is detected.
The enclosed design protects the emitter from moisture, dirt, dust, lint, and debris. Its housing is constructed from durable 7075-T6 aluminum, and the optic carries an IPX7 waterproof rating. It features a 0.83 × 0.55-inch window, weighs 1.62 ounces, and measures 2.44 × 1.02 × 1.10 inches.
Who is it for? The Osight SE MOS is best for owners of compatible Glock Gen5 MOS pistols who want an enclosed optic that mounts directly to the slide without an adapter plate.
Best RMSc-Footprint Osight Optics for the Glock MOS
If you want to run an RMSc-footprint Osight on a Glock MOS slide, you’ll need to use the correct MOS-to-RMSc adapter plate.
RMSc optics are the smaller, less bulky option in the lineup and are generally a better fit for concealed carry. If you want the cleanest and most compact setup possible on a Glock MOS pistol, the RMSc options are a great place to start.
1. Osight SE Red & Green Dot - Direct Fit RMSc Enclosed Carry Dot
Buy the Osight SE At The Best Price
The Osight SE is a compact enclosed-emitter pistol optic designed for everyday carry, concealed carry, home protection, and defensive use. Its fully enclosed design protects the emitter from dirt, moisture, lint, and debris, helping the optic remain dependable in harsh conditions or during daily carry.
Unlike Osight models that use a magnetic charging cover, the Osight SE is powered by a side-loading CR1620 battery. This allows the battery to be replaced without removing the optic or disturbing your zero. Battery life is rated for up to 75,000 hours at brightness setting three.
The Osight SE is available with either a 6 MOA dot or a multi-reticle system featuring a 2 MOA dot and 32 MOA circle. Both reticle options are offered in red or green. The optic also includes eight daylight brightness settings and two night vision settings.
Its housing is made from durable 7075 aluminum, while the aspherical lens is designed to provide a clear, distortion-free sight picture. The optic uses the compact RMSc footprint and weighs just 0.97 ounces, making it a strong option for slimline and concealed-carry pistols.
Who is it for? The Osight SE is best for shooters who want a compact, enclosed optic with replaceable batteries, multiple reticle choices, and strong protection against the debris and moisture commonly encountered during everyday carry.
2. Osight S Red Dot - Enclosed RMSc Optic with Rechargeable Battery
Buy the Osight S At The Best Price
The Osight S is a compact enclosed-emitter pistol optic designed for those who want the added protection of an enclosed design combined with a rechargeable power system. It is very similar in size and overall design to the Osight SE, but instead of using a replaceable side-loading battery, the Osight S is recharged using Olight’s magnetic charging cover.
The charging cover features an integrated battery display that shows the remaining battery level of both the optic and the cover. A fully charged cover can recharge the optic approximately three times before the cover itself needs to be plugged in. The optic provides up to 21,900 hours of runtime at brightness level three while using the 2 MOA dot only.
The Osight S is available exclusively with a red multi-reticle system. You can switch between a 2 MOA dot with a 32 MOA circle, the 2 MOA dot by itself, or the 32 MOA circle by itself. It also includes ten daylight brightness settings and two night vision settings.
The housing is constructed from Olight’s OAL material, which the company claims is 19% harder than 7075 aluminum and offers strength comparable to titanium while maintaining a lightweight design. The optic weighs just 0.97 ounces.
Who is it for? The Osight S is best for those who want a compact enclosed optic with a rechargeable battery system and do not want to purchase or replace disposable batteries.
3. Osight K - Best Budget RMSc Red Dot
Buy the Osight K At The Best Price
The Osight K is a compact open-emitter pistol optic designed as the most budget-friendly option in Osight’s RMSc-footprint lineup. It shares the same general size and window dimensions as the enclosed Osight SE, but its open-emitter construction keeps the design simple and affordable.
The Osight K is available with a 6 MOA dot in either red or green. The larger dot is easy to locate during the draw and works especially well for close-range shooting, concealed carry, and defensive use. It includes eight daylight brightness settings and two night vision settings.
Power comes from a side-loading CR1620 battery. Runtime is rated for up to 63,000 hours at brightness level three. A motion sensor automatically activates the optic when movement is detected and powers it down after three minutes of inactivity to conserve battery.
The housing is constructed from 7075 aluminum and weighs 1.02 ounces, features a 0.83 × 0.55-inch window, and carries an IPX6 water-resistance rating.
Who is it for? The Osight K is best for shooters who want an affordable, lightweight RMSc optic with a simple 6 MOA dot and easy side-loading battery access. It is a strong entry-level choice for concealed-carry pistols, range guns, and anyone who does not need the added protection of an enclosed emitter.
Best RMR-Footprint Osight Optics for the Glock MOS
If you want to run an RMR-footprint Osight on a Glock MOS slide, you’ll need the correct MOS-to-RMR adapter plate. Some Glock MOS pistols were sold with a factory #2 plate, which is the plate Glock uses for the RMR footprint.
RMR-footprint optics are generally a better match for full-size and compact pistols because they have a larger housing and a larger viewing window than the smaller RMSc optics. That extra window space can make the dot easier to find during the draw and gives you a little more viewing area while shooting.
1. Osight C Multi-Reticle Red Dot - Versatile Open Reflex RMR Optic
Buy the Osight C At The Best Price
The Osight C is a full-size open-emitter pistol optic designed as the most budget-friendly option in Osight’s RMR-footprint lineup. Compared with the smaller RMSc models, it offers a larger viewing window and is intended for full-size and compact pistols that use the popular RMR or 407C/507C mounting footprint.
The Osight C is available with either a red or green multi-reticle system. You can switch between a 3 MOA dot with a 32 MOA circle, the 3 MOA dot by itself, or the 32 MOA circle by itself. It includes eight daylight brightness settings and two night vision settings.
Power comes from a side-loading CR1632 battery. Runtime is rated for up to 130,000 hours at brightness setting three while using the dot-only reticle. A motion sensor automatically activates the optic when movement is detected and powers it down after three minutes of inactivity to help conserve battery life.
The housing is made from durable 7075 aluminum. The optic features a 0.95 × 0.75-inch window, weighs 1.48 ounces, and measures 1.77 × 1.18 × 1.18 inches.
Who is it for? The Osight C is best for those who want an affordable open emitter RMR-footprint optic with a flexible circle-and-dot reticle option.
2. Osight XE - Reliable Side-Loading Battery Sight
Buy the Osight XE At The Best Price
The Osight XE is a full-size enclosed-emitter pistol optic built around the popular RMR footprint. Its sealed design protects the emitter from dirt, moisture, dust, and debris, making it a more rugged option for those who want the added reliability of an enclosed optic.
The Osight XE is available with a red Advanced Multi-Reticle System, or AMRS. This system gives you five selectable reticle configurations: a 2 MOA dot, a 6 MOA dot, a 2 MOA dot with a 32 MOA circle, a 6 MOA dot with a 32 MOA circle, or the 32 MOA circle by itself. It also includes eight daylight brightness settings and two night vision settings.
Power comes from a side-loading CR1632 battery. Runtime is rated for up to 105,000 hours at brightness level three while using the 2 MOA dot-only setting.
One of the most unique features of the Osight XE is its integrated collapsible backup rear sight. By pressing the release button, the rear sight pops up and provides a backup aiming reference in case the optic is turned off or loses power.
The housing is constructed from 7075 aluminum, and the optic features a 0.91 × 0.71-inch window. It weighs 1.80 ounces and measures 1.91 × 1.20 × 1.16 inches.
The Osight XE is essentially the battery-powered version of the Osight XR. Both models share the same enclosed RMR design, advanced reticle system, and collapsible backup rear sight, but the XE uses a replaceable side-loading battery instead of a magnetic charging cover.
Who is it for? The Osight XE is best for those who want a feature-rich enclosed RMR optic with multiple dot sizes, a circle reticle, and an integrated backup rear sight, but prefer the simplicity and long runtime of a replaceable battery.
3. Osight XR Enclosed Red Dot - Innovative Magnetic Charging Red Dot
Buy the Osight XR At The Best Price
The Osight XR is essentially the rechargeable version of the Osight XE. Both models share the same enclosed RMR design, multi-reticle system, and collapsible rear sight, but the XR replaces the side-loading battery with the magnetic charging cover.
The Osight XR uses a red advanced multi-reticle system with five selectable reticle configurations: a 2 MOA dot, a 6 MOA dot, a 2 MOA dot with a 32 MOA circle, a 6 MOA dot with a 32 MOA circle, or the 32 MOA circle by itself. This gives you the flexibility to choose a finer aiming point for precision or a larger dot and circle combination for faster target acquisition. It also includes eight daylight brightness settings and two night vision settings.
Unlike the battery-powered Osight XE, the Osight XR uses Olight’s magnetic charging cover. The cover charges the optic without requiring it to be removed from the pistol and displays the remaining battery level of both the optic and the cover. A fully charged cover can recharge the optic up to six times before the cover itself needs to be recharged. The optic provides up to 54,000 hours of runtime at brightness setting four while using the 2 MOA dot-only reticle.
Another standout feature is the integrated collapsible backup rear sight. With the press of a button, the rear sight pops up to provide a backup aiming reference if the optic is powered off or unavailable.
The housing is constructed from 7075 aluminum, and the optic features a 0.91 × 0.71-inch window. It weighs 1.69 ounces and carries an IPX7 waterproof rating.
Who is it for? The Osight XR is best for those who want a feature-rich enclosed RMR optic with multiple reticle options, an integrated backup rear sight, and a rechargeable power system that eliminates the need to purchase replacement batteries.
4. Osight X - Large Window Multi-Reticle Optic
Buy the Osight X At The Best Price
The Osight X is a full-size open-emitter pistol optic built on the RMR footprint and designed for those who want a large viewing window with a rechargeable power system. It is available with either a red or green multi-reticle system featuring a 3 MOA dot and 32 MOA circle.
You can switch between the 3 MOA dot with the 32 MOA circle, the 3 MOA dot by itself, or the 32 MOA circle by itself. The optic also includes 10 daylight brightness settings and two night vision settings.
One of the biggest advantages of the Osight X is its large 0.94 × 0.85-inch window. While the Osight C is slightly wider at 0.95 inches, the Osight X window is noticeably taller, giving it approximately 12% more viewing area overall. That larger sight picture can make the dot easier to find during the draw and help with faster follow-up shots.
Instead of using a replaceable battery, the Osight X is powered by a rechargeable internal battery and Olight’s magnetic charging cover. The cover displays the remaining battery level of both the optic and the cover, and it can fully recharge the optic approximately three times before needing to be recharged itself. Runtime is rated for up to 77,000 hours at brightness setting three while using the dot-only reticle.
The housing is made from Olight’s OAL material, which is designed to offer greater toughness and strength than standard 7075 aluminum while remaining lightweight. The optic weighs 1.62 ounces and carries an IPX6 water-resistance rating.
Who is it for? The Osight X is best for those who want a large-window, open-emitter RMR optic with a rechargeable power system and flexible red or green multi-reticle options. It is especially well suited for range use, competition-style shooting, and anyone who prioritizes a larger sight picture.
Best DPP-Footprint Osight Optics for the Glock MOS
If you want to run a DPP-footprint Osight on a Glock MOS slide, you’ll need the correct MOS-to-DPP adapter plate. Like the RMR and RMSc options, the DPP footprint does not mount directly to the standard Glock MOS cut on its own.
Size-wise, DPP-footprint optics are kind of an in-between option. They’re generally larger than the compact RMSc optics, but not quite as large as some of the full-size RMR options. That makes them a nice middle ground if you want more viewing area without going all the way to the largest optic setup possible.
1. Osight SE DPP - Best DPP Footprint Enclosed Optic
Buy the Osight SE DPP At The Best Price
The Osight SE DPP is an enclosed-emitter pistol optic designed for slides that use the DeltaPoint Pro (DPP) footprint. Its sealed construction protects the emitter from moisture, dust, dirt, and debris.
The optic is available exclusively with a red multi-reticle system featuring a 2 MOA dot and 32 MOA circle. You can switch between the 2 MOA dot with the 32 MOA circle, the 2 MOA dot by itself, or the 32 MOA circle by itself.
Power comes from a side-loading CR1620 battery. The battery tray allows the battery to be replaced without removing the optic from the pistol, helping preserve its zero. Battery life is rated for up to 75,000 hours at brightness setting three while using the dot-only reticle. A motion sensor also helps conserve battery life by activating the optic when movement is detected.
The housing is constructed from durable 7075-T6 aluminum and features a 0.91 × 0.71-inch window. It weighs 1.34 ounces, measures 1.83 × 1.12 × 1.11 inches, and carries an IPX7 waterproof rating.
Who is it for? The Osight SE DPP is best for those who want an enclosed, battery-powered optic for a DeltaPoint Pro-cut slide.
Choosing between Red or Green Reticles
It’s common to go back and forth between red and green reticles, so here are a few practical points to help you decide which one makes the most sense for your setup.
- Green reticles are often easier on the eyes, especially during longer range sessions or extended training.
- Shooters with astigmatism sometimes see a cleaner dot in green. While results vary from person to person, many customers report that a green reticle appears more defined and less “smeared” compared to red.
- Green will not wash out on backdrops like green grass, foliage, or green colors.
- In theory, green dots can have a longer battery life because green is brighter, so for example a green dot on brightness setting 6 may be the same brightness as a red dot on setting 7 - which would save battery life.
If you want to learn more check out our full article about Red vs Green Dot Pros & Cons here.
Choosing between Open vs Closed Emitters
A simple way to think about open versus enclosed emitter red dots is to match the optic to how you plan to run your Glock Gen 5.
If your Gen 5 is going to see a lot of outdoor use in rain, snow, or rough conditions, an enclosed emitter has a clear advantage. The emitter is sealed inside the housing, which helps prevent water, dirt, or debris from blocking the dot when conditions are less than ideal.
For shooters running OWB setups, whether for duty, range time, or general outdoor use, enclosed optics tend to be the safer choice for that added protection and consistency.
If your Gen 5 is primarily carried IWB or used in more controlled environments, an open emitter optic will serve you just fine. They are lighter, simple, and still perform well in most situations, including light weather. Enclosed designs just add an extra layer of reliability when things get messy.
Maintenance is another factor to consider. Open emitter optics can collect dust, lint, and debris over time, especially with daily carry, so occasional cleaning is part of the routine. Enclosed emitters are easier to maintain since the critical components are protected inside the housing.
To learn more about Open vs Closed emitters you can check out our Open vs Closed Emitter Guide here.
How to decide which Osight reticle style is best for you
In this guide we covered a few different reticle options. If you need some help deciding which is best for you here are some of our thoughts on each.
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Conclusion
The Glock MOS is popular for a reason. It gives you a lot of flexibility when choosing a pistol and optic. With the right adapter plate you can run everything from smaller RMSc optics to larger RMR and DPP options.
Hopefully this guide helped clear up which Osight optics will fit your Glock MOS slide and what adapter plates you may need to make each setup work. Whether you want something compact for carry, a larger window for range use, or a direct-mount option like the Osight SE MOS, there are a few different ways to set up your pistol.
If you’re still not sure which optic or adapter plate you need, reach out to us. Our customer service team will be happy to help you figure out the right setup for your Glock MOS.
