Retaining Head, Compatible with Brand Lincoln, Tweco, Series TOUGH LOCK (TM), Gas Diffuser Number 404-20-25, Compatible with Series TOUGH LOCK, Compatible with Model Magnum (R) 300, Magnum (R) 400, Spray Master (TM) 350, Spray Master (TM) 450, Tweco #3, Tweco #4, WeldSkill (R) 400, Connection Type Slip-On, Duty Rating Heavy Duty, Welding Processes MIG Welding (GMAW), Connection Thread Size 9/16 In. -18, Connection Thread Type Slip-On. This item has been restricted from sale in the following state (s): []