Our Nano Disc Air Stone Is Made Of High-Quality White Alundum & Brown Alumina, Fired At A High Temperature Of 1300 Degrees Celsiusthe Air Diffuser Area Is Very Smooth And Exquisite, Not Like Other Poor Quality Air Stone Touch Roughthis Kind Of Air Bubble Stone Has The Following Features: A Super Sturdy & Durable, Service Life Can Be 2 To 3 Yearsa Weighs Enough To Sink In The Bottom, No Need Suction Cupsa Dissolve More Oxygen To The Watera Nice High Output Of Amounts Of Bubblesa Produce Quiet Smooth Dense Small Bubbles In The Watera Strong Filtration, For Fresh And Salt Watera White Color And Disc Shape, A Good Decor For Your Aquariuma Easy To Cleana Comes With Other Accessorieswant To Create Beautiful And Fairy Bubbles Wall In Your Aquarium, Please Buy 2 Or More Different Size Of Air Stonesspecification: 2 Sizes: 2 Inch, 4 Inchweight: The 2 Inch Air Stone Weighs 52Oz150G, The 4 Inch Air Stone Weighs 152Oz430Goutlet Size: 2 Inch Disc Air Stone Can Only Be Compatible With 4Mm Airline, The 4 Inch Disc Air Stone Can Be Compatible With Airline Of 4Mm Or 8Mmcompatible Air Pump Wattage: The 2 Inch Air Stone Can Be Drove By 2W Or Larger Wattage Air Pump, The 4 Inch Air Stone Can Be Drove By 4W Or Larger Wattage Air Pumpwarm Tips: 1 If Have Tubing Frustration, Soak The Tube For Several Minutes Before Connecting It To Air Stone2 To Achieve Better Effect, Please Immerse The Air Stone In Water For An Hour Before Puting It Into Use3 When The Water Depth Exceeds 13Ft (40Cm), You May Need An Air Pump With Higher Power Wattage 4 Cleaning Tips: We Suggest To Clean The Disc Once A Month, Of Course You Can Clean It More Often You Need To Clean Algae And Other Impurities On The Disc To Prevent Holes Blocked