Perfect gravel cleaner for fish tank or aquarium to clean gravel, siphon the fish excreta and other dirt out effectively without requiring a water change. Powered by two batteries, safe to use. Features: Easy to install and operate. Press the on/off button on the top, the water in aquarium will be pumped out automatically through a hose for changing water. Also can clean gravel, siphon the fish excreta and other dirt out effectively without requiring a water change. The upgrade outlet water head and scraper are convenient to clean the dirt in the corner and on the wall. Powered by two batteries, safe to use. Another power on/off button to control external power supply(not included). With adjustable structure, it is suitable for small and large aquariums. Note: Ensure to reach the lowest water level when start working, after the power is on, the water level does not have to reach the lowest water level. Specifications: Material: Plastic Power Supply: 2 * C Batteries(not included) Flow Rate: 520L/h Max Water Depth: 72cm Package Size: 41 * 12.5 * 7cm / 16.1 * 4.9 * 2.8in Package Weight: 366g / 12.9oz Package List: 1 * Set of Gravel Cleaner