Three Modes: The 3-in-1 aquarium cleaning tool sucks water, removes algae and cleans gravel.^ Multi-purpose design: The gravel cleaner can install battery and be used directly by adapter. suitable for medium and large aquariums.^ Easy Installation and Operation: Installed gravel cleaner, please keep the water level between MAX(60cm) and MIN(11cm), then start the switch. The water in the aquarium is automatically pumped out through a hose to change the water.^ Cleaning Function: Can also clean gravel that effectively siphons out fish waste and other debris without requiring a water change.^ Feature and Accessories: High safety performance, only need 2 C size alkaline batteries (package not included). The blue hose length: 75cm^