Multi-Fuel: Uses (1) Streamlight SL-B26 protected Li-Ion USB rechargeable battery pack; also accepts (2) CR123A lithium batteries; TEN-TAP Programming allows for selection of three different operating programs: 1) high/strobe, 2) high only, 3) low/high; High: 800 lumens, 648m beam distance, runs 2 hours (SL-B26), runs 1.5 hours (CR123A); Low: 55 lumens, 174m beam, runs 26 hours (SL-B26), runs 18 hours (CR123A); Strobe: runs 3.5 hours (SL-B26), runs 2.5 hours (CR123A); Integrated rail clamp attaches to MIL-STD-1913 (Picatinny) rails - Easy to attach, secure mounting; Durable, anodized aluminum construction with impact-resistant Borofloat glass lens; IPX7 waterproof to 1 meter for 30 minutes (without remote pressure switch installed); IPX4 water-resistant (with remote pressure switch installed); Limited lifetime warranty; "System" - Includes mounting hardware, M-LOK mount, momentary switch and (2) CR123A batteries