Features: OOTDTY Safe Material: This aquarium air stone can be washed and used for a long time repeatedly. It is made of acrylic, safe to use to maintain the health and vitality of fish. Small Size: The air diffuser can easily disappear from view and save space with its transparent, compact design. Quietly Generates Dense Small Bubbles: This aquarium air stone can calmly generate a very dense cloud of small bubbles in the aquarium to create a dazzling curtain effect. High Dissolved Oxygen: The fine air bubbles allow oxygen to dissolve in the water, which is a great way to add oxygen, lower carbon dioxide levels, and keep your fish healthy. Easy to Use: 1 strong suction cup makes the co2 diffuser firmly adhere to the water tank. Suitable for home, office aquariums, aquariums and hydroponic nutrient tanks. Specification: Material: AcrylicColor: TransparentSize (Approx:P.) Size (Approx.) 3.5cm / 1.38in Suction Cup Diameter 4x2.5cm / 1.57x0.98in Air Diffuser Height 7.5cm / 2.95in M-air Disc Diameter 1.6cm / 0.63in L-air Disc Diameter 2.5cm / 0.98in Weight (Approx.): M-20gL-25g Package Included: 1 x Aquarium CO2 Diffuser (M/L)1 x Adjusting Valve1 x Suction CupNote: 1. Please allow 0-1cm error due to manual measurement. Pls make sure you do not mind before bidding.2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!