Delivering day or night command and control with convenient AA battery power. The EOTech HWS 558 works with all Gen I-III night vision devices and features an adjustable, locking, quick-detach mount for instant removal. Ergonomic, side operational buttons make this HWS ideal for use with EOTECH’s quick, flip-to-side magnifiers and adjustment activation without removing your strong hand. NIGHT VISION COMPATIBLE L X W X H 5.6” x 2.2” x 2.9” (142.3 x 55.9 x 73.7 mm) WEIGHT 13.8oz (391.2 g) WATER-RESISTANT 33 ft. (10 m) depth MOUNT 1” Weaver or MIL-STD-1913 rail BRIGHTNESS 20 daylight settings10 additional settings for Gen I through III+ night vision devices POWER SOURCE 2 x 1.5 V AA batteriesSupports CR123, alkaline, or rechargeable BATTERY LIFE CR123: 2,500 continuous hours at nominal setting 12 at room temperature.AA alkaline: 2,200 continuous hours at nominal setting 12 at room temperature. COUNTRY OF ORIGIN Made in USA