SureFire LED Weaponlight For Mossberg 500 and 590 Shotguns Virtually indestructible LED regulated to maximize output and runtime 80 Lumens for 3 hours of Tactical light Two 123A Lithium Batteries SwitchesMomentary-on pressure pad, constant-on rocker ConstructionHigh-strength aerospace aluminum with Mil-Spec anodizing; impact-resistant polymer; coated tempered window WeatherproofO-ring and gasket sealed