Watts Aqualock 1/4 In. ODx1/4 In. FIP PEX Pipe Quick-Connect Adapter. This easy-to-install adapter features corrosion-resistant teeth that allow it to interconnect with multiple materials without special tools or tube inserts. Suitable for hot and cold water applications, it works with copper, CPVC, PEX, LPDE, MPDE, HDPE, and polybutylene tubing.