An innovative tubeless dot sight that is Waterproof, Fogproof and Shock-proof on firearms up to .50 caliber. At a mere 2 oz, you won't even know it's on your gun. NcSTAR features unlimited eye relief, easy target acquisition, and a light-sensitive rheostat for brightness control. The sight is fully adjustable to compensate for windage and elevation. A special lens coating completely eliminates double-dot or split images. This sight also utilizes low power consumption technology for extended battery life. When a battery does have to be replaced, there is no need to remove the sight. Simply unscrew the protective cover that houses the battery, pop in the new one, and your good to go. This red-green dot sight is ideal for shotguns, handguns, paintball guns, airguns and crossbows. Backed by a Manufacturer's Limited Lifetime Warranty Electronic Sight Features Tubeless Design With 25mm Reflex Lens Aperture Provides A Wide, Crisp Field Of View Multi-Color Red/Green 3 Brightness Settings per Color Parallax Free With Unlimited Eye Relief Allen Head Screw Type Windage and Elevation Click Adjustments, With Locking Screw Water-Proof, Shock-Proof and Fog-Proof Low Power Consumption/ Long Battery Life Light Weight; Scope and Mount Together Weigh Less Than 5oz Lifetime Manufacturer's Warranty