CPVC 1/2 in. CTS Compression Transition Adaptor Insert. Used to stub out with CPVC from a brass compression fitting. All conventional metal plumbing systems corrode leaving their corrosive wastes for deposit into the water system. CPVC thermoplastic system components never corrode. KBI/Spears CTS CPVC system of fittings, pipe, supply stops, valves & solvent cement are Certified lead-free by NSF® International (NSF®) in accordance with ANSI/NSF® 61 and NSF®372 for compliance with all State & Federal Regulations. Approved by national, state and most municipal building codes and listed by ICC to ASTM E84 for Flame & Smoke Characteristics of less than 25/50 for use in return air plenums. KBI/Spears CTS CPVC products are ideally suited for hot and cold water distribution systems in residential and commercial structures, as well as recreational vehicles, modular homes and mobile homes.