The Easypro CAS Compact Aeration Systems are reliable continuous duty aeration systems for ponds and water gardens up to 2000 gallons. Featuring whisper quiet CMC series air compressors, these systems provide air circulation, elevate oxygen levels, and provide deicing. All while operating at volume above a whisper and using only pennies of electricity a day. Each system comes with 2 diffusers, making these aeration systems perfect for ponds with irregular shapes. The included check valves install inline and protect the pump from suffering water damage incase of power failure and the subsequent back pressure. <br> <br> What's in the box?<br> CMC5 Adjustable Flow Air Pump - 2 year warranty<br> Two 25' rolls of 3/16" ID Airline<br> Two 4" Airstone Diffusers w/ check valves<br>