Oxyclone 20 System, Simple, Compact, Recirculating Cloning System, Works With A Variety Of Cuttings, Allowing You To Have A Perpetual Garden Year Round, Powered By Active Aquas Premium, BPA Free Water & Air Pumps, Submersible Pump Delivers Constant Turbulence To Your Reservoir While The Attached Venturi Valve Naturally Draws In Air Bubbles, For Maximum Aeration, Single Outlet Active Aqua Air Pump Provides A Constant Flow Of Dissolved Oxygen Through A Circular 4" Air Diffuser.