Matala Diffuser Base w/ 9" Air Disc Matala offers a full line of air diffusers that are perfect for any lake aeration, koi pond, water garden, aquaculture or waste water treatment project. Our rubber membrane disc diffusers range from 3 inch to 12 inch diameter and offer the highest quality on the market with only 4 inches of back pressure added. With their self-cleaning ability and minimal maintenance requirements, you'll be sure to enjoy years of trouble-free operation. Choose between options with or without a weighted base for your convenience. Our Matala Tube Diffusers also come in three sizes (12in, 24in & 39in) - each available in either a weighted or non-weighted version. The EPDM membrane ensures low back pressure and small to medium size bubble production - enhancing the performance of your system. Don't settle for anything less than the best - invest in Matala air diffusers today! FEATURES The air diffuser platform mounts diffuser firmly to bottom of pond up out of any mud. Hollow base is filled with sand or gravel and water to weigh it down Highest quality EPDM rubber membrane on the market. Disc membrane is the lowest back pressure membrane diffuser on the market. Handles airflow 0.9 - 4.2 cfm / 25 - 120 lpm. Recommended for 25 lpm - 80 lpm air pumps. SPECIFICATIONS Model MDB-11 Air Volume LPM/CFM 40-120LPM 1.4-4.2CFM Platform to Diffuser Qty 1:1 Package Dimension 310x140x270mm / 12.2x5.5x10.6 Inches Gross Weight 3.3lbs Opening Your Pond-free Waterfall