VERY100 Holographic Reflex 4 Reticle Red Green Dot Sight Scope 21mm Rail Mount with Waterproof Box(Black) Screen Size: 22mmx33mm;Weight: 130g; Length: 82mm Reflex Sight Reticle Type: Circle Dot, Cross, 10 MOA & 3 MOA(Red and green illuminated) 4 reticle patterns offer unlimited eye-relief and corrected parallax Allen Wrench included helps you adjust elevation and windage easily. Made of high grade Aluminum Alloy, the dot sight is durable and Light weight.