Trijicon HD XR Tritium Night Sights - Rear - Yellow Front Outline - for GLOCK Models 20 21 29 30 and 41 including S & SF variants Black. Building on the features of the current HD Night Sights the Trijicon HD XR night sights are for the next level of advanced target identification and engagement at increased distances. A thinner front sight post allows shooters to have a larger field of view which further enhances the ability to identify targets expedite engagements and see location of hits on target at longer distances. Pistol shooters that need the advantage of a more precise engagement in any light can count on the Trijicon HD XR Night Sights. Specifications for Trijicon HD XR Tritium Night Sights - Glock Large Frames MOS: Manufacturer: Trijicon Gun Make: Glock Gun Model: Glock 21 Glock 30 Glock 29 Glock 20 Color: Black Rear Sight Color: Black Sight Style: U-Notch Fabric/Material: Steel Gun Type: Pistol Attachment Type: Slide Front Blade Height: 0.215 in Rear Blade Height: 0.321 in Height: 0.268 in Illumination Type: Tritium Illumination Color: Green Features of Trijicon HD XR Tritium Night Sights - Glock Large Frames MOS EXPANDED FIELD OF VIEW AND A PRECISION SIGHT PICTURE FOR LONGER-RANGE ENGAGEMENTS. Thin front post (.122 in. width) promotes a larger field of view for fast target identification and engagement at longer distances. ENHANCED FRONT SIGHT ACQUISITION IN BRIGHT TRANSITIONAL AND NO-LIGHT SITUATIONS. Glow-in-the-dark photoluminescent-painted front outline combines with a subdued "U" notch rear to quickly draw your eye to the 2X brighter domed sapphire/tritium front sight in all lighting conditions. INSTANTLY VISIBLE SIGHT PICTURE IN NO-LIGHT AND LOW-LIGHT SITUATIONS. Tritium phosphor-filled glass lamp illuminates sights for high visibility in all lighting conditions. ENHANCED PROTECTION FROM HEAVY RECOIL AND HARSH CLEANING SOLVENTS. Tritium gas lamps are contained within protective aluminum cylinders and have additional silicone rubber cushioning. 2X BRIGHTER FRONT SIGHT. The front sight features a domed-shaped sapphire cap that focuses the tritium illumination for a 2X brighter aiming point. EVENLY DISTRIBUTED LIGHT FROM TRITIUM LAMPS. Each Trijicon tritium lamp is capped with a sapphire jewel that helps evenly distribute the light and also acts as an additional layer of protection from puncture and cleaning solvents. Package Contents: Trijicon HD XR Tritium Night Sights - Glock Large Frames MOS 1 - Front Sight 1 - Rear Sight 1 - Front Sight Screw Trijicon GL645-C-601169: HD XR Tritium Night Sights - Rear - Yellow Front Outline - for GLOCK Models 20 21 29 30 and 41 including S & SF variants Black