EOTech Holographic Sights feature a heads up design that allows both eyes to be open in order to maintain peripheral vision and depth perception while shooting. The best just got better. Get all of the features found in EOTech's top sight, the EXPS, but now with easy to find AA batteries. The 518 is compatible with the LBC (Laser Battery Cap) and with the buttons on the side, it mates close with the magnifier to reduce rail space. Notes:Auto Battery Check Indicator: Flashing reticle upon startup if batteries are at 20% of battery life.Auto Shutdown: At 8 hours programmable to 4 hoursRevision F ElectronicsRubberized Input ButtonTwo year manufacturer's warranty from date of purchaseFeaturesEasy adjust side buttonsAdjustable, locking quick-detach lever fits both 1" Weaver and MIL-STD-1913 railOperates on 2 common AA Alkaline or Lithium batteriesLBC compatibleMagnifier compatibleSubmersible to 10ft (3m) depth