TK09 features our exclusive Tactical Tap switch which provides instant access to momentary-on, constant-on and output selection. Knurled for easy grip, suitable for rail mounting, the grip ring equipped TK09 excels in demanding situations. Features Cree XP-G2 (R5) LED with a lifespan of 50,000 hours Uses one 18650 rechargeable Li-ion battery or two 3V CR123A Lithium batteries 130mm (Length) x 25.4mm (Body Diameter) x 34mm(Head Diameter) 114-gram weight (excluding the battery) Reverse polarity protection guards against improper battery installation Tactical tail switch with momentary-on function Made of durable aircraft-grade aluminum Premium Type III hard-anodized anti-abrasive finish Toughened ultra-clear glass lens with anti-reflective coating