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. Specification Color: Copper Tone Material: Copper Type: Copper Reducer Bigger End Inner Dia.:38mm / 1 1/2 inch Smaller End Inner Dia.:32mm / 1 1/4 inch Thickness.: 1.5mm / 0.06 inch Total Length: 44mm / 1.73 inch Packing List: 2 x Copper Reducer Advantage Made 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. Instruction Just clean and flux the pipe and fitting, then heat with a torch and apply solder. Allow to cool before handling. NOTE Please 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. HVAC and Refrigeration tubing is measured by it's outside diameter, while plumbing tubing is measured by it's inside diameter, please confirm the size carefully before purchasing.