The Eheim Quick Vac pro is a battery powered gravel cleaner which enables you to clean the gravel substrate in your aquarium with ease, independently of your regular of water changes. The suction power of the cleaner is designed to remove dirt particles without too much disturbance to the gravel. A mesh filter compartment collects the dirt whilst letting the water flow back into the aquarium. The filter compartment is simple to remove.Eheim Quick Vac pro Sludge extractor+ easy and safe to use (no power cables)+ fully submersible with watertight on/of switch for use with all shapes and sizes of aquarium+ suction power specially designed to pick up dirt particles without excessively disturbing gravel+ super fine filter sieve captures even the smallest dirt particles while letting water back into your aquarium+ can be used in fresh water and marine water aquariums with a water depth of approx. 60 cm+ Aquarium gravel not coarser than2 mm+ not suitable for cleaning sandy bottoms