The G&G ES DR 1-4x Optical Sight is a fully functional replica of sight used by U.S. special forces. The sight features the ability to toggle between 1x (no magnification) to 4x magnification making it ideal for airsoft use - with merely the flip of a lever. It also looks amazing. Features a red/green illuminated reticle and integrated iron sights. Attaches to any standard picatinny top rail system. This is a really awesome airsoft scope.This is an airsoft specific scope and NOT to be used on real guns. It's not meant to endure recoil from an actual firearm.