Monstrum Tactical R01C Red Dot Sight with 4 Reticles and Red/Green Illumination The R01C is an open reflex sight with a compact, lightweight design fit for mounting on rifles, shotguns or even pistols Four selectable reticle patterns, illumination in red and green, and multiple brightness settings, for a clean sight picture regardless of lighting conditions or environment Flexible eye relief, suitable for almost any shooter or firearm Mounts easily to any Weaver/Picatinny rail system Sturdy anodized aluminum construction with black matte finish