Fenix TK15 features a powerful, tough, durable and fully waterproof design intended for harsh outdoor conditions. Operating on two CR123A Lithium batteries or one 18650 Li-ion battery, the multi-level dimmer function makes a perfect combination of extreme brightness and ultra long run time. The innovative side dimmer operation is very simple and rapid. Therefore TK15 will be the reliable partner when hunting, searching and rescuing. Features of Fenix TK15 Cree XP-G LED(R) with lifespan of 50000 hours . Three modes, two types of output for each mode, selected by Side dimmer button. Turbo - 337 Lumen, 1 hour 50 minutes, high-143 Lumen, 6 hour 25 minutes, medium-47 Lumen, 23 hours. Low - 5 Lumen, 142 hours, strobe- 337 Lumen. Deep-dish reflector for long beam distances. Digitally regulated output - maintains constant brightness. Battery reverse-polarity protection. Side dimmer button. Powered by two 3V CR123A or one 18650 lithium batteries not included.