The Mastervision L.E.D. Cap light is powered by 2 lithium coin cell batteries for approximately 75+ hours of ultra white light from 3 L.E.D. bulbs with 100,000+ hours of burn time each. New strobe mode and 2-way switch allow for 600+ hours on strobe mode on one set of batteries. Lightweight, only 1.0 oz. with batteries, water resistant.