Pawfly 4-inch air stone disc is a great way to add oxygen to your aquarium, fish tank and circulation system. MODEL: ASD-100. Jetting Volume: 12 L/min, suitable for approx. 15.7-39.4 inch fish tank. Standard pressure 0.01 MPa, Max pressure 0.012 MPa. Using this with an air pump that runs 3.2 LPM - 25 LPM. Fits for 0.16" / 4 mm inner diameter tubing. Recommended Air Pump Power: 4W-8W. Measures 4-inch width by 1-inch height. Safe, Washable & Durable, Non-toxic material keeps fish healthy and safe. Comes with 3 easy-mount suction cups to make it easily suck in the smooth aquarium.