... of spiral line, all these prevent the pulse noise and vibration. What's more, by using the Impedance complex muffler, the noise ... make the interchangeability of parts and components increased.4. Low vibration. Although the rotor has been processed precisely, and are all ... since it is balanced precisely, it is almost without any vibration.12. Case Material: HT200, Impeller Material: QT400.13. Widely ...