Trijicon's HD XR Night Sights take the advanced features of their Bright & Tough line and further improve upon them. To increase acquisition speed, the HD XR series sights feature a a bright, orange photoluminescent outline of the tritium lamp. For better identification of targets and hits at increased distance, the XR series also features a more narrow front sight. The subdued rear sight has been steeply hooked to assist with one-handed emergency slide operation. Green lamps are warranted for 12 years from the date of manufacture. DISCLAIMER: "GLOCK" is a federally registered trademark of GLOCK, Inc. and is one of many trademarks registered by GLOCK, Inc. and GLOCK Ges.m.b.H. Neither AR15Discounts nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.m.b.H. The use of any "GLOCK" trademarks on this page is merely to advertise the sale of pistols, parts, components or accessories that are compatible with GLOCK pistols. For genuine GLOCK, Inc. and GLOCK Ges.m.b.H. products and parts visit www.glock.com