Retaining Head, Compatible with Brand Tough , Series TOUGH LOCK(TM), Gas Diffuser Number 404-18-25, Compatible with Series TOUGH LOCK, Connection Type Slip-On, Duty Rating Standard Duty, Welding Processes MIG Welding (GMAW), Connection Thread Type Slip-On, For Use With Bernard Air-Cooled and T- Water-Cooled MIG Guns, Fume Extraction MIG Guns, Tregaskiss Robotic Air-Cooled and Water-Cooled MIG Guns, Material Brass, Maximum Wire Diameter 0.125 in, Minimum Wire Diameter 0.023 in