The 3 Pack of Shunting Bio Filter Media is designed for aquarium filtration, specifically for ponds or tanks with a water capacity suitable for fish and other aquatic creatures. The foam/sponge filter media provides a 50 PPI (pores per inch) rating, allowing for efficient filtration and maintenance of water quality. With dimensions of 6" x 6" x 1.57", these internal filters are compatible with all water types and offer a reliable filtration solution for any aquarium setup.