A very dense pad great for use in all wet dry filters or to make your own DLS Filter Rolls. Removes particulate matter to make aquariums sparkling clean and clear. Retains debris and large particles to prevent clogging of polyester filters. Rugged and 100% reusable. Water sparkles clean and crystal clear with Pure Flow Filter Pads. These sanitized, polyester pads are interwoven with nylon fibers, making them durable, reusable and highly effective. They retain debris and large particles in both fresh and saltwater to prevent the clogging of biological filter media. Can be cut to fit any mechanical filter. 36"x24"