The Ameriglo SW145: Night Sights Classic are constructed from precision-machined steel, with a tritium front and rear, as well as striking white outlines. The model features GL-112 front and GTR 650/690 rear. It is designed with a rear notch measuring .150\" and a front blade width of .140\".Made from bar stock steels sourced within the US, AmeriGlo sights are assembled with Swiss-produced tritium light sources. They are internationally used by law enforcement agencies, military personnel, security-conscious free citizens, and those who engage in recreational shooting.