OASE BIOMASTER EXTERNAL FILTERExternal Aquarium Filter For the Highest Demands EasyClean pre filter module Module can be removed separately from the rest of the filter. This reduces maintenance, increases filter efficiency, and extends the life of main filter foams. Customize the pre filter with coarse 30 ppi, fine 45 ppi, ultra fine 60 ppi, and activated carbon 45 ppi filter foams No mess maintenance Integrated safety locking features on the handle, pre filter, and check valve in