Powered by two 3-volt CR123 lithium batteries with 10-year storage life C4® LED Technology, impervious to shock with a 50,000 hour lifetime. Up to 7,000 candela peak beam intensity and up to 135 lumens measured system output. with Strobe feature Up to 2.5 hrs runtime (laser-only mode runs 45 + hrs.) Rail grip clamp system securely attaches/detaches quickly and safely with no tools and without putting your hands in front of muzzle Fast, Adjustable, Secure Side mounting to 1913 and Glock style Rails Machined aluminum sealed construction with black anodized finish Dustproof Ambidextrous momentary/steady on/off switch Highly accurate sight repeatability when remounting Fits existing light bearing holsters 4.72 oz. Lithium Battery Notice under TECH DOCS