Please kindly noted that this item is sold by JSrong from Joybuy marketplace. The fish tank automatic water replenisher is a device designed to automatically fill and maintain the water level in a fish tank. It is compact in size, measuring 1.421.421.38 inches, which makes it easy to fit into any fish tank setup. The device is made from high-quality ABS material, ensuring durability and long-lasting performance. Installation is convenient and does not require drilling holes. The water level controller operates on the principle of differential pressure, allowing for timely and accurate water replenishment. It also features a water level adjustment function, which enables users to easily adjust the water level according to their needs. With this automatic water replenisher, fish tank owners can enjoy a hassle-free and convenient way of maintaining the ideal water level in their tanks. Size:1.42"*1.42"*1.38". Small size, convenient to store and carry, no drilling required, easy to install Made of corrosion-resistant ABS material, which is also usable in saltwater. Screw-free, no damage to the tanks It very easy to use, practical and interesting. Simply screw the compensator onto the water bottle and stick it to the water tank When the water level drops to reveal the shorter tube, the water in the bottle automatically flows into the tank due to pressure difference Better than a float valve, no wiring or power required, takes less space