The Streamlight ProTac Rail Mount VIR USB Pro Weapon Light with SL-B9 Battery Pack delivers versatile rifle-light performance with visible white light, IR illumination, and adaptable mounting hardware for tactical platforms. White-light output reaches 1,100 lumens with 40,000 candela and a 400 m beam, while the head-mounted selector allows quick switching between visible and IR modes. Jack-Cap switch redundancy, BOROFLOAT glass, and Picatinny or M-LOK compatibility help support dependable field use.