11/20 mm holographic sightmain characteristics: Built by aluminum alloy with matte black anodized treatment. weight lightweight and compact design, waterproof and shockproof. Anti Glare reflective coated lenses that gives good optical clarity. Tubeless design with openings 22x33mm SLR lens provides a wide field of view. a 3 position dimmer control (Red and Green). installed 4 different reticles (Dot Circle, Cross, 10 and 3 MOA MOA) for maximum versatility. vis head drift type