Trijicon designed this HD XR Front Sight for FNH 40 Pistols as the next level of advanced target identification and engagement at increased distances. This thinner sight post allows shooters to have a larger field of view that enhances their ability to identify targets, expedite engagements, and see hits at longer distances. The device features a green battery-free tritium phosphor lamp surrounded by a photoluminescent yellow outline disk. For durability, the lamp is encapsulated in an aluminum cylinder with a silicone rubber cushion and covered with a sapphire window. The window acts as a beam-shaping lens and protects the lamp from solvents that are commonly used to clean firearms.