(Ship from CA USA) Aquacity Bio Sponge Filter Media Pad, Cut-to-fit Foam for Aquarium Fish Pond Reef Canister Tank Cut-To-Fit filter media Bio Sponge. Can be cut to fit your filters. Size: 17.7"x 17.7"x 1.8" or 23.6"x 17.7"x 1.8" Good for both biological and mechanical filtration - offers more surface area for the beneficial nitrifying bacteria to colonize, eliminate toxic compounds and improve water quality ; trap large bits of waste, and will not get clogged easily.