Tregaskiss Tough Gun™ 403-1-45-25 MIG Gun Consumable, Heavy-Duty Contact Tip, Style: Threaded, 5/16 Inch Outer Diameter x 1.344 Inch Length, Connection: 5/16-18R, Wire Size: 3/64 Inch, Amperage: 450/650 amp, For Type/Brand/Model: Robotic Water-Cooled Quick-Change MIG Guns