High Output Sintered Airstone High quality sintered airstone that will give a rich micro bubbles of oxygen. Airflow dependent on depth of Pond and output of airpump. Pond H2o 2 1/2 Inch (64mm) Heavy Duty Air Stone Cylinder for Larger Pump Bubble Diffuser for Outdoor Pond Garden Circulation System Aquariums, Aquatic, hydroponic, fish tank or Any aeration need. Fine Bubbles: The air stone produces lots of rich micro bubbles of oxygen. A great way to oxygenate your hydroponic growing systems, koi fish ponds, water gardens, aquariums and enliven the aquatic life and create a healthy habitat. Made of minerals that are sintered at a high temperature, to encourage longer lasting product. Perfect for both fresh and salt water environments like fish tanks, water gardens, bird baths, ponds, DWC reservoirs, aquariums and more. Airflow dependent on depth of Pond and output of airpump. Pump required, Not Included ? Length is 2.5 inch - 7 cm ? 3/16th And 5/16th Fittings ? Sintered Airstone Material for Long Life and Fine Bubbles ? High Quality Sintered Airstone that will Give a Rich Micro Bubbles of Oxygen. Airflow Dependent on Depth and Output of Airpump Terms and Conditions. We use all approved payment methods. Sales Tax will be added to all shipments, based on regulations. We always try to combine purchases, please contact us directly for a personal service. You will be notified on the day that your goods have been dispatched via e-mail with tracking which is used on all purchases. Please note that if there are any problems, contact us first via e-mail giving full details of any problem along with your user ID. We use USPS and UPS as our chosen carriers shipments to Hawaii, Alaska Puerto Rico may incur surcharges, contact will be made to advise before shipment at which point the order can be canceled if desired. Orders placed on Saturday/Sunday Public Holidays will be processed next working day. We pride ourselves on excellent feedback, if any part of the buying experience is not to your satisfaction, please contact us to rectify before leaving feedback. By committing to buy you are agreeing to the Terms Conditions stated above.