Crain 979 Universal Welding Tip is versatile and works with a 3 mm or 5 mm round welding rod, "half-moon" ("half-round") welding rod, or a triangular welding rod. It has an adjusting screw at the rod inlet to adapt the inlet to the various rod shapes. The grooved brass pressure roller is also adaptable to the various rod shapes. The hot air inlet is sized to fit the Crain No. 960 Heat Weld Gun (Leister Triac ST) or previous model No. 980 Heat Weld Gun, as well as other popular models of heat weld guns.