The AC pipe jointers are designed to connect two copper pipes without welding. This flare fittings can also be applied in fuel and gas systems, plumbing, refrigeration, and vacuum applications. Note: Usually there are two different sizes copper tubes in the AC system. We need to purchase corresponding size pipe connectors to match the two pipes. Specifications: Item: AC pipe joint Connector Material: Brass For Pipe Size: 1/4" (6.35mm) and 3/8" (9.53mm). Package Included: 1 Pack x 1/4" AC pipe joint Connector 1 Pack x 3/8" AC pipe joint Connector