These copper fittings are good for use in a variety of plumbing applications, including water supply, HVAC system, refrigeration system, water heating system etc. These copper fittings can work on type M,L or K copper tubing. Copper Fittings are Manufactured to Standard ASME B16. 22AdvantageMade from pure copper, these fittings are durable and long lasting. The reducing design allows for the connection of pipes with different diameters, providing versatility in plumbing installations. The sweat solder connection ensures a secure and leak-free joint.InstructionJust clean and flux the pipe and fitting, then heat with a torch and apply solder. Allow to cool before handling.NOTEPlease note that the sizes we mentioned are all actual sizes, not the nominal size. For example, the 1 inch copper elbow has 1"(25.4mm) ID size, suitable for connecting 1"(25.4mm) OD copper pipes, not suitable for 1" nominal copper pipe which has 1-1/8" OD size. Please confirm the size before purchasing.