Tetra Whisper Air Pumps for aquariums provide powerful, dependable airflow. Efficient and easy-to-use, Whisper Air Pumps are available in a range of sizes to handle the aeration needs of aquariums from 10 to 100 gallons. Tetra Whisper 40 Air Pump (non-UL) can be used in tanks 20 to 40 gallons. The Whisper Air Pump's patented dome shape and sound-dampening chambers minimize turbulence and produce a smooth, quiet stream of air. Its wide footprint, rubber feet and suspended pump motor eliminate sound-producing vibrations. Thick walls insulate motor noise, and powerful diaphragms provide ample airflow for deep water applications. Uses standard-size aquarium tubing. Select the proper size air pump for your tank.