For shotguns, rifles or pistols, this compact sight with 5 MOA red dot is fully waterproof and shockproof. The all aluminum red dot has a self-regulating brightness control, meaning there is no on/off switch. A photocell on the front of the sight powers the sight up when it is exposed to light. Simply remove the included cover and the sight turns on, replace the cover and the red dot will shut off. The supplied riser block positions the sight at optimum height on AR-15 flat tops.