Uses (1) Streamlight SL-B50 protected Li-Ion USB-rechargeable battery pack (included); Features TEN-TAP Programming - Choice of three user selectable programs: 1) high/strobe, 2) high only, 3) low/high; High: 2000 lumens, 583m beam, runs 2.5 hours; Low: 250 lumens, 214m beam, runs 11 hours; Strobe for Signaling or Disorienting: runs 4.5 hours; IP67-rated; dust-tight and waterproof to 1 meter for 30 minutes; 2-meter impact resistance tested; 6000 series machined aircraft aluminum with Type II MIL-Spec anodized finish; Mounts directly to guns with MIL-STD-1913 (Picatinny) rails; Limited lifetime warranty; Includes mounting hardware, M-LOK mount, momentary pressure switch, (1) SL-B50 battery pack and USB-C cord; "System" model