Waterway TWM Above Ground Swimming Pool Cartridge Filter - (Choose Size). The cartridge filter provides homeowners with everything they need to get their system up and running. It assures them of matched components and optimal performance with years of dependable service. Our TWM above-ground filters incorporate wide-body filtration elements to give maximum filtration without sacrificing the flow rate.Replacement cartridge for TWM Cartridge filter system - Choose from 50 sq. The item "Waterway TWM Above Ground Swimming Pool Cartridge Filter (Choose Size)" is in sale since Wednesday, March 11, 2020. This item is in the category "Home & Garden\Yard, Garden & Outdoor Living\Pools & Spas\Pool Equipment & Parts\Pool Filters". The seller is "savemoreonpoolsupplies" and is located in Tonawanda, New York. This item can be shipped to United States.