WOLTIS RC 1X32 Fiber Optic Red Dot Sight / Green Dot Sight Scope With QD Mount Please use it in the daytime and in the ourdoors. Because the power source fiber needs enough light, it can not be used in dark environment, the light indoors is not strong enough for it, thank you! Suitable for any 20mm RIS weaver standard rail. Illuminated aiming dot that automatically adjusts the brightness based on available light Full metal casting with rubberised matte black finish. Windage and elevation adjustment (1/4" click @100 yards).