Honest air pump for the money. It is quite powerful. At full, it mixes everything up! Fortunately, it comes with an air flow regulator (external). It has one output but with a splitter you will have a second air output. For small/medium aquariums it is more than enough, maybe even excessive. And yes, it is quite silent. Compared to my old mouse type that used to drive the world crazy. It does not include a non-return valve so you have to purchase it separately.