Marineland Magnum Bonded Pad Filter Media is specially designed to prolong the life of filter media by reducing the accumulation of waste and dirt particles. The pad’s porous, open-cell construction promotes water flow without impairing overall filter performance. It’s made of durable interlinked coarse and fine polyester fibers that are locked together with a tough bonding agent to catch a wide range of suspended debris, keeping the filter clean and the aquarium water clear.12″ x 24″ Cut to fit any filter, canister or sump