The union features solder cups. The fitting is used to allow repair to the line without damage as well as adapt from a solder connection to a threaded connection. In addition to its inherent qualities of beauty, durability and low maintenance, coppers reusability makes it an ideal application in sustainable projects. Nibco® copper fittings are backed by a 50 years limited warranty. Because of its longstanding reputation for innovation and precision in design and manufacturing, Nibco® is the preferred brand in the industry.