... by using the Impedance complex muffler, the noise of our blowers are further reduced. 2. High volume and anti-heat efficiency ... high precise and hardness Synchronization gear, we not only extension blowers life, but also reduce its noise.6. Our blower ... : QT500-7.13. Widely used in many fields, especially in gas transportation, waste water treatment, aquaculture, pneumatic transport, vacuum packing, ...