Tube Calibre : about 4mmVoltage : NoneModel Number : bubble air stoneMaterial : Gold steel sandType : FishPower : NoneUsage : increase the air volume in water40/50/60/70/80/100mm Bubble Stone Aerator for Aquarium Fish Tank Pump Hydroponic Oxygen Plate Mini Air Pump Accessories Features:Ozone aerated stone, bubble stone, using super hard gold steel sand, after high temperature sintering, good gas diffusion, good filterability, ozone resistance, corrosion.Increase oxygen levels, lower CO2 and raise PH, creates water currentsIt is an important instrument to successfully keep aquatic fish for respiration process.Durable, can be reused and washed repeatedly.Creates bubbles in fish tank while attached to an air pump(air pump and air tube is not included).Specifications:Color: Grey, Grey with 120cm black tubeMaterial: hard gold steel sandItem Size: Approx. Dia. 4cm/5cm/6cm/7cm/8cm/10cm/12cm/15cmPackage include: Only 1*air bubble stone/stone with 120cm black tubeSuitable for inner diameter 4mm soft tubeFor another kind of aquarium air stone, please click Round Aquarium Air Stone:https://www.aliexpress.com/item/32920956587.htmlNote:-Soak in water for 15 minutes before use.-For long-term use, if there is dirt blockage, and the bubbles is reduced, please take it out of the fish tank and wash it again and again.-The air stone can be used repeatedly.-Please allow 1cm differs due to manual measurement.-Due to the different display and different light, the picture maybe a little different with the actual color of the item. Thanks for your understanding.1pcs aquarium fish tank air stone/stone with 120cm tube