The Tru-Dot Tritium Night Sight for H&K USP FS from Meprolight is a sight system with glowing dots that are visible under any light condition, including total darkness. When used as a complete set, the three dots align horizontally, forming an easily discernible sight-alignment. The sight can withstand stout recoil, harsh field conditions as well as solvents. This model is compatible with H&K USP full-size pistols, and includes a rear sight with yellow dots and front sight with a green dot.