The Mepro MPO-DF is an open reflex red dot sight specially designed for full-sized pistols. This cost-effective optic punches far above its cost. It features a 3.5 MOA ret dot reticle RMR footprint automatic and manual brightness controls CR1632 battery lasting 2 years plus while being water shock and fog proof makes this optic stand out from the crowd. The Mepro MPO-DF allows you to upgrade your current sighting system with money left over for more ammo. The Meprolight name means we only produce products we ourselves use and carry in defense of ourselves and our families. Choose the best choose Meprolight.