The AQQA glass mounted dual power sponge filter is perfect for multiple aquarium up to 55 gallons. The outlet is telescoping and directional so you can adjust the water/air flow to the desired level and direction.
There's no need to connect an air pump to this filter due to the built in pump which efficiently pulls water through the sponges, through the bio media and out of the directional output.
These filters feature a unique compartment beneath each sponge for the included bio media to provide additional surface area for the growth of beneficial bacteria.
One of the best things about this filter is the fact that it can be mounted on the glass on the back or side of the aquarium so as to not interfere with Aquascaping. See dimensions in the photo.
Each filter comes with an extra sponges which is great because you can clean one while using a fresh sponge or if you have fish that like to nip at the sponge you have a back up once the original is deteriorated.