About this item POWERFUL: Tetra Whisper Air Pump provides dependable airflow to your aquarium. QUIET: Patented dome shape, suspended motor and sound-dampening chambers for quiet operation. PROVIDES OXYGEN AND WATER MOVEMENT: Keeps underwater pets happy. AVAILABLE SIZES: Select the proper size for your tank – 10, 20 and 40-gallon pumps have single air outlets, 60 and 100-gallon pumps feature dual outlets. NON-UL LISTED: Reliable performance at an economical cost.