XS R3D Night Sights feature a traditional 3-dot tritium" notch and post sight picture. The blacked out rear increases contrast against the front sight. Available in orange or green" the front sight ring is equipped with their Ember Glow Dot Technology which absorbs ambient light and glows in low light. R3D sights are the brightest options for fast and accurate shooting in bright and low light. Green is the best option for low light and has the brightest glow intensity. Orange contrasts the best in bright light settings while still maintains visibility in low light. The front sight tritium lamp is brighter than the 2 rear sight lamps" reducing the possibility of mixing up the front sight tritium vial with a rear sight vial in low/no light. The front blade measures 0.145" (3.68 mm) wide" and the rear notch is 0.170" (4.32 mm) wide" which increases the visibility of the front sight. R3D sights are installable by sight pusher tools or by using a hammer and punch. Fits Springfield HellCat OSP.