Long life and low-frequency operation for continuous use.Locate Unit above Water Level to Prevent Water Flowing Backwards (or fit with a non-return valve)3 Speed settings: High, Medium and LowRubber feet for noise reductionAdvanced air compression system and shock absorption system. Multi-stage muffler design, low noise. The use of special synthetic rubber components, air volume, pressure constant. Environmentally friendly design, no oil lubrication. Compressed air is quite pure. Reasonable and compact structure, best efficiency with lowest power consumption, economy and power saving, long service life.What’s in the box – 1 x BOYU Sc-7500 Double Outlet Air Pump