Perfectly designed to fit the Ultramax external range the sponges are available in 3 grades to ensure the optimum water clarification can be achieved.The Standard Sponge ensures optimum water flow whilst still removing medium to large particles from the water.At a GlanceDesigned for the Aquael Ultramax 1000, 1500 and 2000100% None ToxicStandard Grade SpongeEffective Biological and Mechanical Filtration