Tweco® Slip-On Nozzle with a 3/4" bore size fits standard gas diffuser and is designed to use for 450 A Tweco® Spray Master® MIG guns. 3.21" Nozzle has a 0.875" OD and is used in heavy-duty welding applications for up to 450 A. It features part number rolled stamped on the outer surface for easy identification. Nozzle with a recess contact tip relationship 0.125 - 0.156" that is used where longer electrical stick-out is needed or when the nozzle touches the work place is made of 122 DHP copper alloy. It has a 3-piece design that includes a nozzle housing that is cut and formed from copper alloy tubing, a nozzle insert machined from a solid brass and nozzle insulator constructed of silicone material. It has nozzle insert that allows it slide over a metal spring of the gas diffuser. Nozzle offers electrical insulation required from the gas diffuser using the nozzle insulator and is sold as 2 per pack.