The Whisper® Air Pump’s dome shape actually flattens sound wave frequencies. In addition, each model features sound dampening chambers designed specifically for that model. The air pump's rubber feet and suspended motor prevent sound waves from reflecting off surfaces such as tables and shelves. Available in models that cover tanks from 5 to 100 gallons, Whisper® Air Pumps provide a powerful flow of air. For Aquariums up to 60 gallons.