Powered by two 3V CR123A lithium batteries w/10-year storage life. Shockproof 3-watt Luxeon LED w/blinding beam (up to 80 lumens) w/bright side-light-will not break or burn out. 2.5 hrs. runtime (laser mode runs 45+ hrs.). Rail grip clamp system securely attaches/detaches quickly & safely w/no tools. Fast, adjustable, secure side mounting to 1913 & Glock style rails. Machined aluminum sealed construction w/black anodized finish. Waterproof to one meter for one hour, dustproof. Ambidextrous momentary/steady on-off switch. Highly accurate sight repeatability when remounting. Fits existing light bearing holsters.