The HWS EXPS2 maximizes rail space with its compact design and provides co-witnessing with iron sights. Convenient side buttons make it simple to pair with a magnifier, while its adjustable, locking quick-detach lever ensures fast, secure attachment and easy removal for ultimate versatility.Specifications and Features: L x W x H: 3.8" x 2.3" x 2.9" (96.5 x 58.4 x 73.7 mm) Weight: 11.2oz (317.5g) Mount: 1" Weaver or MIL-STD-1913 rail Windage & Elevation Adjustment: 0.5 MOA per click Night Vision Compatibility: No Brightness: 20 daylight settings Power Source: 1 x CR123 battery Country of Origin: Made in USA