The COLD-X cold expansion brass PEX-A adapter is simple to install. COLD-X Expansion PEX barb fittings are a key component to one of the most economical potable water piping systems. Also capable of integration into hydronic heating systems, COLD-X Expansion PEX couplings must be secured into place COLD-X Expansion PEX sleeves or comparable expansion-type sleeve or ring (all sold separately). The COLD-X system is a comprehensive piping system comprised of lead free brass fittings, poly alloy fittings, manifolds, valves, fasteners, tools and tubing designed for implementation in water delivery systems, simple or complex. A cold-expansion tool (sold separately) is required for installation.