The DRGB135U is a Small Tube Tactical Red, Green, and Blue Dot Reflex Optic with a Cantilever Mount. The Cantilever Mount will mount onto nearly any Weaver/Picatinny type rails. The red Dot has an LED (Light Emitting Diode) 100% safe for the eyes, multi-position rheostat knob for red/green/blue dot illumination with three brightness levels and unlimited eye relief for flexible mounting. Includes battery and mounting tools. Includes battery and mounting tools.