This is one bright light. Quite frankly it's amazing this much light can be generated from one AAA in this Gerber Triode LED headlamp. Using the button located conveniently on top, one can turn this light on and off, or from low beam to high beam. It can be deployed on the bill of your cap, or you can use the adjustable head band that Gerber includes.Light Source: 3 L.E.D.Output Color: WhiteHousing Material: ABS Resin:1 AAA battery included