The Trijicon HD XR Night Sights were specifically designed with the ever evolving challenges of law enforcement agencies in mind. 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. Green tritium lamps are warranted for 12 years from date of manufacture. Professional installation recommended. Fits Sig Sauer models calibrated for 9mm and .357SIG and pistols that come factory standard with #8 Front/#8 Rear. Front Sight Width: 0.122″. Front Sight Height: 0.279″. Rear Sight Height: 0.309″.