XS Sights, R3D 2.0, Tritium Night Sight, For Glock 20/21/29/30/30S/37/41, Orange Front Outline, Green Tritium Front/Rear WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov. For Glock 21 Orange Ring Tritium front and rear sight Black nitride surface finish DIYer Install Rated Dual-Illuminated tritium photoluminescent front sight High contrast orange or green photoluminescent Glow Dot Anti-glare Blacked-out Serrated Rear Sight Rear Sight Ledge for one-handed slide manipulations Traditional notch and post 3-dot sight picture CNC-machined iron sights Made in U.S.A. Product Description The second-generation R3D night sights are engineered to give you a brighter, stronger set of sights. Easily install your sights with a set that requires 50% less force for installation. R3D 2.0 sights are built to withstand years of EDC use and abuse. The set drives focus downrange using a serrated blacked-out rear sight and a dual-illuminated tritium photoluminescent front sight. R3D 2.0 sights are the brightest notch and post option for fast and accurate shooting in bright and low light.