Relations Feature A 21mm Quick Release Picatinny Mount A Four Kinds of Reticle A Reticle Lock System A 6 Levels Red Dot Specification A Magnification: N/A A Objective Lens Dia: 28x40mm A Length: 92mm (3.6 inch) A Weight (net): 168g (6.0 ounce) A Eye Relief: Free A Field of View (@100yds): 80&&';; A Optics Coating: Multi Coated A Reticle: 4 patterns A Elevation Range: 40MOA A Windage Range: 40MOA A Click Value: 1MOA A Illumination:6 levels red A Battery:LR44 A Mounting:21mm Quick Release picatinny mount A Reticle exchange with audible clicks A Reticle locking system hard recoil support A Low battery power consumption for longer battery life A Shock proof (750g), Rain Proof and Fog Proof A High-durability aluminum alloy in black matte A Install on 21mm picatinny mount base