EOTech Holographic Weapon Sight Model 518™ DescriptionThe absolute best just were given better. The 518 runs on easy to seek out AA batteries but offers all the features found in EOTech’s EXPS top of the road sight. With side button functionality you’ll reduce rail space when partnering the 518 with an EOTech magnifier. The 518 may be compatible with the brand new drop-in Laser Battery Caps that EOTech designed to beef up aiming through the usage of visible and IR lasers. Product DetailsLength/Width/Height: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:Submersible to 10 ft. (3 m) depthMount:1” Weaver or MIL-STD-1913 railBrightness:20 daylight settingsPower Source:Two 1.5 V AA batteriesSupports lithium, alkaline, or rechargeableBattery Life:Lithium: 1,000 continuous hours at nominal setting 12 and room temp.AA alkaline: 600 continuous hours at nominal setting 12 and room temp.