UCO A-45 Comfort Fit LED Headlamp Thinnest, lightest, most comfortable headlamp on the market; Fits (circumference of head): 21-26 inches (53-65 cm) Unique, no "hard point" hinge design fits your head perfectly and allows the lamp to focus forward or down towards the ground Headache Free-Soft, adjustable neoprene strap with hook/loop adjustment for a custom, comfort fit Dial provides infinitely adjustable brightness on CREE XP-D LED up to 11 lumens plus red night vision mode; Burns up to 200 hours Battery Type (included): Two CR2032 Li; Bulb Type: Super bright XP-D CREE LED; Highly Water Resistant: IPX 4; Weight (with batteries): 1.6 oz. (45 g)