Specification: Ultrafire 501B Cree XML T6 1000 Lumen 5-Mode LED Flashlight (1*18650 )Emittor type: Cree XML T6 Reflector:OP Aluminum Drop-in LED Circuit: Direct Drive Runtime:600lumen/90minutes Mode: Low/Mid/High/Strobe/SOS Switch type:Tactic Click Reverse Swith Configuration Material: Aluminum voltage input range: 3.7V 4.2V