500 lumens; 140m beam; runs 1.5 hours. Custom optic produces a concentrated beam with optimum peripheral illumination. TLR-7 side switch model cannot be retrofitted to the the TLR-7A X rear switch models. Uses one CR123A lithium battery (included). Safe off feature prevents accidental activation; saves batteries. Rail grip clamp system securely attaches/detaches quickly and safely with no tools and without putting your hands in front of muzzle. Durable, anodized machined aluminum construction. User enabled strobe function. 2.58 (6.55 cm); 2.4 oz (68.1g). IPX7 waterproof to 1m for 30 minutes.