The Viridian RFX-25 is an open reflex micro green dot (1x) for pistols on the Docter / Burris FastFire / Vortex Venom footprint (not RMR). It runs a 3 MOA green dot through a 20x28mm window with Instant-On activation, manual brightness, and auto shut-off. The 6061-T6 housing is IPX6 rated and a Picatinny adapter is included. Features: Open reflex micro green dot (1x) for pistols Docter / Burris FastFire / Vortex Venom footprint (not RMR) 3 MOA green dot 20x28mm window CR2032 battery, up to 30,000 hours Instant-On activation, manual brightness, auto shut-off 6061-T6 aluminum, IPX6 rated Includes a Picatinny adapter Confirm your slide is cut for the Docter/FastFire pattern before ordering.