The main characteristic is that the problem of the different caliber of the metal pipeline connection is solved, and the function of damping and noise reduction is also provided, which can save the installation part and save the cost of the pipeline. It consists of an inner rubber layer and a nylon cord Bu Zengqiang, rubber ball outer layer composite and the loose metal flange. With high voltage, good elasticity, large displacement, balance pipe deviation, absorb vibration, noise reduction effect is good, installation is convenient wait for a characteristic, widely used in water supply and drainage, circulating water, HVAC, fire protection, paper, pharmaceutical, petrochemical, ship, water pump, compressor, fan pipeline system. Air, compressed air, water, sea water, sea water, oil, acid, alkali, etc. are used for conveying the 15 C to 120 C. The special type is used for conveying the medium or the oil, the concentrated acid and the solid material, and the solid material, which is more than 30 degrees Celsius to 250 degrees Celsius.