Style 88 Couplings and Fittings are handy, ready-to-use boltless connectors specially designed for use with copper tubing. However, Style 88 fittings can be used for CTS PE x PE connections ONLY with the recommended Dresser lock insert stiffener. Call Dresser Customer Service for recommendations. Each Style 88 fitting consists of a brass, malleable or steel body, as usage dictates; two rugged malleable or brass end nuts; and two resilient ARMORED gaskets, protected against damage from threads by gasket retainer cups. Gaskets are made of our exclusive Dresser rubber compound, with helical coil armors. All castings are 100% air-tested to assure a leak-proof seal.