The REIN is a powerful and durable complete weapon light system . It features a field serviceable lens, a field-serviceable tailcap, electrically-isolated dual-switching for redundancy and a modular 3-piece design that makes the REIN upgradeable over time. The REIN comes standard with a push-button in the tail cap, the switch offers both momentary-on and constant-on capability. Includes Rein, Picatinny rail mount, mounting hardware, Defensive labeled Nitecore Charger, Micro USB to USB cord and a Samsung 30Q 18650 battery.