-The sponge filter are made of excellent and perfect material, it can be reused for long time. -The sponge filter are designed by multilayer principle, it has large surface, which will not cause blockage and could be wash easily. -When using in filter system, the sponge filter will not cause any noise pollution. -When using air stone which will produce air supply for the aquarium tank, it will increase oxygen level in the tank. -The sponge filter had gone through tough test in all expected situation for the perfect quality. -The sponge filter is suitable for all Freshwater fishes, like Discus, Tetras, Guppy, Arowana, Betta Etc...