These copper pipe fittings are widely used on water plumbing, air conditioner, heat pump system, and refrigeration system. It is a hardware for sealing the end of your copper pipeline. Advantage: The copper pipe fitting is made of copper material, with good thermal conductivity. Have a good performance on transferring the Heat. Smooth surface and no burrs. Instruction: Cleaning the connection surface, and then soldering to install. NOTE: Need to confirm the pipe size before ordering.