Feature: 1. Multifunctional: Electric aquarium water changer removes gravel, removes dirt from the bottom of the tank and changes the water. 2. Safe: This aquarium vacuum water changer is safe, energy efficient, and powered by an AC adapter or 2 C batteries (not included). 3. Water Changer: Fish tank vacuum cleaner can be used as a water changer and shut off after siphoning. Easily drains fish tank dirt. 4. Retractable Design: Aquarium gravel cleaner with retractable design, easy to adjust, suitable for different size of fish tank. Easy to install and operate. 5. Note: Clean the filter bag in time after cleaning the gravel (it is consumable, if it can't filter properly due to damage, please replace it with a new one). Specification: Item Type: Aquarium Water Changer Material: ABS Plug: EU Plug, Rated Voltage: 100-240V Battery Type: 2 x Dry Cell Battery Type: C Type Batteries (Shipped without Batteries). Package List: 1 x One Piece Motor3 x Telescopic Conduit1 x Mesh Bag Interface1 x Filter Bag1 x Siphon Tube1 x Sand Washing Cup1 x Plug1 x Instruction Manual1 x Moss Removal Brush Note: 1. Please use our professional adapter for external power supply.2. Do not work continuously for more than 30 minutes to avoid burnout.3. This product is designed using the siphon principle, and cannot pump water from low water level to high water level.4. When draining, the highest point of the drain pipe must not be higher than the starting water level line, otherwise the product cannot pump water normally.5. Please allow for some errors due to manual measurement.