2 1/4" overall. CREE XP-G R5 LED. Three modes: low - 20 lumens with 14 hour runtime; medium - 50 lumen output with 4 hour runtime; and high - 170 lumen output with 1 hour runtime. 69m beam distance. Uses one CR2 lithium battery (not included). Includes keyring and spare O-ring. SENS Outdoor Series. Aerospace-grade aluminum alloy construction with anodized black HAIII mil-spec finish. Body is knurled for a sure grip. Features: Active dimming system with auto-adjust function; Soft turn-on mode and low illumination for everyday usage; convenient one-handed operation; Integrated lens; Reverse polarity protection; and tail stand capability. Waterproof in accordance with IPX-8 (Submersible to two meters). Impact resistant to 1.5 meters. Tail stand capability. Boxed with hanging tab.