Type schematic (not to scale) of a MIG nozzle, labelled with the printed size and nozzle mount cited in the specifications below; this part's outside diameter, bore and length are not in our sources.
Bernard N1B34Q MIG nozzle
Bernard N1B34Q Nozzle 3/4", Brass, Thread-On: size 3/4 in, material Brass, nozzle mount Thread-On.