NIBCO 1" x 1/2" Reducing Coupling with Stop is a copper coupling designed specifically for copper pipe plumbing systems. It effectively joins two sections of copper pipe with different diameters while featuring a built-in stop to prevent the pipe from being inserted too far, ensuring a secure and proper fit. I for soldering or sweating applications, this coupling allows the copper pipes to be heated and soldered together, creating a watertight and durable joint that you can rely on. Model Number: W00800D