4.4" overall. Impact resistant. Water resistant. Clip. Tailcap switch. LED. TIR lens. Coated tempered window. White light modes: High (250 lumens, 1.5h runtime), Low (5 lumens, 20.5h runtime). IR modes: High (100 lumens, 4.75h runtime), Low (5 lumens, 57h runtime). Requires (1) CR123A battery (included). Aluminum construction.