The Mepro MPO-DS is an open reflex red dot sight designed for subcompact or slimiline pistols. This cost-effective optic punches far above its cost; featuring a 3.5 MOA red dot reticle, RMSc/JPoint footprint, automatic brightness controls, a CR2032 battery lasting 3 years, and being water, shock, and fog proof, this red dot sight can't be beaten. The Mepro MPO-DS allows you to upgrade your current sighting system with money left over for more ammo. The Meprolight name means they only produce products they use in defense of self and family. Specifications: Footprint: RMSc/JPoint Objective Lens Diameter: 0.82"W x 0.58"H Reticle Type: Dot Reticle Size: 3.5 MOA Reticel Color: Red Auto Brightness: Yes Battery Type: 1x CR2032 Battery Battery Life: 30,000+ Hours Windage/Elevation Adjustment: Non-Detent Infinitely Adjustable Windage/Elevation Travel: 80 MOA Operating Temperature: -4AdegF to 158AdegF Waterproof: IPX7 Fog Proof: Yes Weight: 0.6oz