Features: High Efficient Aquarium Air Stone Disc: The fish tank air stone disc designed fine high density holes can perfect produces steady tiny bubble and increase oxygen rate under water, good for fish, shrimp, create healthy aquarium environment. Low Noise Air Stone Disc: The aquarium air stone disc designed with bubble blow out, low noise which suitable for small fish tank & household aquarium. Selected Material: The air stone disc use qualified ABS-plastics material, nontoxic, tear & wear resistant, bring effectively oxygen aeration for your aquarium, fish tanks. Universal Air Tubing Connection: The aquarium air pump disc designed with standard connection applicable for 4mm-8mm pipe(NOT included), leakproof and tightly fitted. Durable Aquarium Air Pump Accessories: The aquarium air pump disc with durable material, 5 optional size to choose, which fit for variety size fishtanks, can meet your daily requirements, fine oxygen diffuser for small fishtank. Specifications: Product Dimension: As pictures shown Material: ABS-plastics Style Option: 35mm/50mm/80mm/100mm/150mm Net Weight: Approx. 35g/0.07lbs Package Includes: 1 x Aquarium Air Stone Disc note: Please allow 1-2cm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color of the item.