TPU(thermoplastic polyurethane elastomer), the material is with the features of good low temperature resistant and ozone resistant for long time usage and comfortable contacting to patient. Low circulation resistance: with the design of isometrical waterway and shuffling stream, fast water circulation and high effective heat exchange are assured. Well, reducing water route is easy for whirlpool so that flow resistance and residual are increased, so as to decrease heat exchange. Fast plug: Reliable connection, fast and easy pull and plug.