Fluval U1 Aquarium Internal Filter 250L/h for tanks up to 55L. Designed for aquariums up to 55L. Suitable for aquariums up to 55L. In addition, the filter can be installed vertically against the aquarium wall to create currents or customized flow patterns; or it can be placed horizontally in shallow water tanks; or it can be used to create decorative features such as waterfalls.
eBay