Koi Pond Aeration/Aquaponics / Hydroponics; Medium Pore {140 Microns} Air Diffuser/Bubble Stone 100% Glass-Bonded Silica Air Diffuser {Self-Weighted} Model #0020 Air Diffuser Measures: 1 1/2" x 1 1/2" x 1 1/2" with 3/16" barb; "standard" air line connection. {Recommended 0.25 CFM or 7 lpm} The "Industry Standard" in Aeration for Fish Farms and Hatcheries Worldwide. This high-quality air diffuser will simply replace, {unplug theirs - plug ours in}, the cheap import diffusers that are included from the factory on the following manufacturers models: PondAir2 and PondAir4; Aquascape Pro60; EasyPro EPA1 and EPA2; LifeLine LL-12; KingMas 3W Pond Aerator; CHICHO Solar Air Pump; and Others not listed. Durable, Long Lasting and Requires Very Little Maintenance. Bubblemac Air Diffusers Provide The Highest Oxygen Transfer Efficiency. Much Higher Than The Blue Chinese Import Air Diffusers. These High-Quality Air Diffusers WILL NOT FALL APART! Made In The U.S.A. "This may not be the LAST air stone you purchase, but rest asurred, it will be with you for a while! **High-Quality/High-Performance Products** "Bubblemac - An American Made Company" Simply Put, The Highest-Quality Air Diffuser On The Market Today. "Ya'll Got Bubbles"? - SPECS: 100% Glass-Bonded Silica, Maximum Pore Size 140 Microns, Nominal Partical Retention 50 Microns, Bubble Size 1-3 MM, UNLIMITED LIFETIME When Used in pH of 8.0 or Less!