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; featuring a 3.5 MOA red dot retice, RMR footprint, automatic and manual brightness controls, a CR1632 battery lasting two years, and being water, shock, and fog proof, this optic stands out from the crowd. The Mepro MOP-DF allows you to upgrade your current sighting system with money left over for more ammo. The Meprolight name means they only produce products they themselves use and carry in defense of self and family. Specifications: Footprint: RMR Objective Lens Diameter: 0.89"W x 0.68"H Reticle Type: Dot Reticle Size: 3.5 MOA Reticle Color: Red Brightness Settings: 8 Auto Brightness: Yes Manual Brightness: Yes Battery Type: 1x CR1632Battery Battery Life: 15,000+ Windage/Elevation Adjustment: 1 MOA Windage/Elevation Travel: Plus/Minus 50 MOA / Plus/Minus 70 MOA Waterproof: IPX7 Fog Proof: Yes Weight: 1.2oz