Stop noisy pipes from banging with the Sioux Chief Mini-Rester - Female swivel adapter connects to a 7/8 inch ballcock outlet of a toilet tank. 7/8 inch male ballcock outlet allows to connect a standard water supply connector or riser. Best installed upstream of all quick shutting valves and faucets. Sioux Chief Mini-Rester design incorporates a poly piston with 2 EPDM, silicon lubricated O-rings, which moves inside solid copper chamber and creates a pressurized cushion of air, completely sealing off the water, which prevents the loss of air in the chamber. Certified by ASSE to the ANSI/ASSE 1010-2004 Standard.