Maintaining zero without needing kid gloves treatment is the idea behind the Aimpoint® PRO (Patrol Rifle Optic) Red Dot Sight. It's built to mount quickly and will light up and stay working for up to 3 years on a single battery. The 2 MOA red dot gives you both-eyes open targeting speed and accuracy at all distances while the hard anodized aluminum alloy housing withstands drops, even into water depths reaching 150 feet. The recessed lens opening prevents impact damage, smudges and scratches and the front and rear flip covers keep the lenses clean. Modular mount works on a number of flat-top, AR-15, M4 and M16 rifles and will not deform your rail.