The Reducing Coupler is available in 1/2" x 3/8" CTS size for use in the domestic plumbing market. Manufactured from high-quality engineered plastic with an EPDM O-ring, the coupler satisfies both hot and cold water plumbing/remodeling and hydronic heating applications. Suitable for use with any combination of copper, PEX, or CPVC pipe, this fitting doesn’t require tools to make a leak-proof connection. The coupler also incorporates Twist and Lock technology providing users with extra security. Both lead free and corrosion-free, this product is NSF and IAPMO approved in the U.S. and Canada. Offered in two sizes 3/4" x 1/2" CTS and 1" x 3/4" CTS. John Guest USA.