Customized production products are produced according to customers' demands. Muffler means that for the airflow pipes with noise transmission at the same time, noise reduction devices such as pipes and elbows with sound-absorbing lining or pipes with sudden change of cross-sectional area and other sound impedance discontinuities can be used to make the noise in the pipes be attenuated or reflected back. Muffler is mainly composed of muffler tube, muffler piece, upper and lower sealing plate (or head), rainproof cap, throttle pipe, throttle plate, connecting pipe (or flange), support, lifting ring, nameplate and other parts. Muffler is a device that can effectively stop or weaken the sound from spreading outward while allowing the airflow to pass.