TRIJICON NS SUP SET for GLK 20 B/B: Trijicon Bright & Tough Night Sights are three-dot iron sights that increase night-fire shooting accuracy by as much as five times over conventional sights. Equally impressive, they do so with the same speed as instinctive shooting - and without the need for batteries Features : Tritium-Phosphor lamp Sapphire window White rings Silicone rubber cushion Protective aluminum cylinders Suppressor sights Back up iron sights Fits GLOCK 20 GLOCK is a registered trademark of GLOCK Inc. 3CR Tactical is not affiliated with, endorsed by, or sponsored by GLOCK Inc. Any reference to GLOCK products is for identification and compatibility purposes only.