AIR STONE BUBBLE STONE AQUARIUM OXYGEN STONE AIR STONE DISC BUBBLE DIFFUSER FISH TANK AIR STONE High-quality material, sturdy and durable , higher dissolved oxygen than usual air stone. ABS thermoplastic air inlet, resistant against corrosion, shiny and easy to clean. Even, uniform and refining air outlet, can be washed repeatedly. Can 4mm diameter air supply. It is suitable for 90-220cm size aquarium or fish tank. PACKING LIST 4 x air stones BUBBLE STONE If you are looking for a professional and affordable fish tank bubble diffuser disc then your research is over here. That's because our product can meet your need. Adopted from premium material it is practical and durable for long time use. It is not easy to get deformed and bring you much convenience. AQUARIUM OXYGEN STONE Color: As Shown Material: ABS and Size: 12.00X12.00X1.90cm/4.72X4.72X0.75in Connector diameter: 4mm/8mm Tank size: 90220cm High quality material, sturdy and durable , higher dissolved oxygen than usual air stone. ABS thermoplastic air inlet, resistant against corrosion, shiny and easy to clean. Even, uniform and refining air outlet, can be washed repeatedly. Can 4mm diameter air supply. It is suitable for 90220cm size aquarium or fish tank.