Power with as little noise as possible. All the aquarium air pumps that we stock are exactly that. Abyss Aquatics is a bricks and mortar walk in store and we would be the first to know if there was an issue with with any of the products that we sell. We of course try them ourselves prior to stocking them. However unlike online only retailers we have the extra knowledge gained from conversing face to face with our customers. So if we would not use one ourselves or sell one to one of our visiting customers. We also would not sell them online. Rest assured any of the Air Pumps listed here are quiet and reliable.