300′ of 1 2″ Polytubing Ultrasonic Four Disc 9" Rubber Membrane Solar Four Disc 9" Rubber Membrane Diffuser with Self Sinking Base Designed to sink without adding rocks or sand to your diffuser base The Wind Driven Aeration System offers:New “BalCam II” technology minimizes bearing fatigue with new Stainless Steel componentsPatent pending new designFast & Easy AssemblyManufactured with high quality 18 gauge galvanized steelNewly redesigned blades and front dome assembly for better air flowSelf governing head to protect the unit in high windsNew secure locking mechanism that attaches the windmill head to shaftLarger check valves and upgraded ½” airline to handle the increased air that is producedHigh Air Output – 3 We do not recommend using this in a pond as it floats We recommend using only weighted airline in a pond