Below are Holosun's K-Series optics offered at the best price with free shipping and returns. These optics include the 407K, 507K, and 507K ACSS Vulcan.

These optics have a modified RMSc footprint a.k.a. K Series footprint.

They have 50k hours of battery life, come in red or green reticles, have shake awake, are IP67 waterproof, have strong 7075 T6 aluminum housings, and have side removable batteries.

The 407K has a 6 MOA reticle, the 507K has the MRS Reticle, and the 507K ACSS Vulcan has the ACSS Vulcan reticle.