Penn Plax Cascade 500 GPH Floss Pads, 24 Pads Total (4 packs with 6 pads in each pack) 24 Pads Total (4 packs with 6 pads in each pack) Convenient, no-fuss replacement pads for your Cascade canister filter. Helps extend the life of your carbon and biological filters. Traps particular matter keeping your aquarium clean & clear.