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^WARNING: BUTTON/COIN BATTERIES ARE HAZARDOUS. KEEP OUT OF REACH OF CHILDRENSwallowing or placing a lithium button battery inside any part of the body can cause severe injury or death in 2 hours or less.Swallowing or placing a non-lithium button battery inside any part of the body can cause serious injuries.Medical attention should be sought immediately if you suspect that your child has swallowed or placed a button battery inside any part of the body.Call the 24-hour Poisons Information Centre on 13 11 26 (Australia) or 0800 764 766 (New Zealand) for fast, expert advice.Regularly examine devices and make sure the battery compartment is correctly secured, e.g., that the screw or other mechanical fastener is tightened. Do not use if the compartment is not secure.Dispose of used batteries immediately and safely out of reach of children.