Biochemical sponge materials: Food grade materials, absolutely safe and easy to clean, and the water tank is 75 liters. Biochemical sponge: Provide an excellent biofiltage effect, without noise during operation, hold the circulation of clean water. Cut: DEEP 4.8 cm x Height 7.8 cm, the inner diameter of the sponge: 1.5 cm; The original sponge, the replacement product is very suitable for sponge filters. The replacement sponge helps improve the biological load capacity and reduce maintenance, increase the oxygen content, to provide the ideal place for bacterial resale, helping to keep the aquarium clean. Large Biochemical Sponge for Path Fish, Fries, Red Fish, Young Fish, Shrimps, Small Fish, Reproduction Aquarium; SUGGESTION: Replace every 5 to 6 months. Amount: 4pcs