Features: brand new and high quality Safe material: This aquarium air stone can be washed repeatedly and used for a long for time. It is made of acrylic, safe to use to maintain the for health and vitality of fish. Small size: The air diffuser can easily disappear from view and save space due to its transparent, compact design. Quietly Generates Dense Small Bubbles: This aquarium air stone can quietly generate a very dense cloud of small bubbles in the fish for tank to create a dazzling curtain effect. High Dissolved Oxygen: Fine air bubbles allow the oxygen to dissolve in the water, which is a great way to add oxygen, lower carbon dioxide levels and keep fish healthy. Easy to use: 1 strong suction cup, makes the co2 diffuser stick firmly to the water for tank. Suitable for home, office fish tanks, aquariums and hydroponic nutrient tanks. Package Includes: 1 x CO2 Diffuser for Aquarium (for M/L) 1 x Regulating for Valve 1 x Suction Cup Specifications: Material: Acrylic Color: Transparent Size (Approx.): Suction Cup Diameter 3.5cm/1.38in Regulating for Valve 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-20g L-25g note: 1.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!