Connect pieces of different-size PEX-A pipe together. Corrosion- fitting certified for use in potable water and hydronic heating system applications. Made from high-performance Acudel Polymer. Warning: This product can expose you to chemics including Carbon-black extracts, which is known to the State of California to cause cancer, and Bisphenol A (BPA), which is known to the state of California to cause birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov. -