The Holographic Weapon Sight (HWS) EXPS3 is an excellent choice for professionals. The EXPS3 offers true two eyes open shooting for fast target acquisition, night vision compatible settings, and a 7mm raised quick detach base for lower 1/3 iron sight co-witness. Specifications: Dimensions: 3.8"L x 2.3"W x 2.9"H Weight: 11.2oz Water Resistant: 33ft Mount: 1" Weaver or MIL-STD-1913 Rail Windage & Elevation Adjustment: 0.5 MOA per Click Brightness: 20 Daylight & 10 Additional for Gen 1 through 3+ Night Vision Devices Power Source: 1x CR123 Battery Battery Life: 1,000 Continuous Hours at Nominal Setting 12 at Room Temperature Operating Temperature: -40AdegF to 140AdegF Country of Origin: Made in the USA Reticle: Eotech One Dot Reticle- Eotech's most popular offered, the 68 MOA ring with 1 MOA dot provides three usable aiming points