2.5″ overall. Strobe. Water resistant. Lanyard. CREE XM-L2 LED. High light transmission TIR lens. Spectrum finish titanium body with PVD stainless ring on the switch and bezel. 110m beam distance. Modes: Level 1 (550 lumens, 2h runtime), Level 2 (60 lumens, 8.5h runtime), Level 3 (12 lumens, 64h runtime), Level 4 (0.5 lumen, 3 day runtime). Requires (1) CR123A battery (included).