The nozzle is made from brass and can be soldered to a copper tube using plumbers solder. Let the solder wick up into the nozzle during heating otherwise the carefully formed internal profile will become filled with solder. Remember that the diameter of copper tubing is based on the ID so a 1/2” sweat fit nozzle will fit a thick wall 3/8” copper tube, etc. Annealed copper tubing tends to be coiled and has to be straightened well before inserting into the nozzle for soldering, Straight copper tubing tends to be hardened and does not bend easily, unless you flame anneal it. The exit apertures are made small at 0.125″ diameter to allow you to open up to your preferred jet diameter before soldering.