Features: Function: When traveling on business or traveling, use the automatic water compensation device to avoid water shortage in the fish tank and aquarium. Convenient to Use: The fish tank water filler is easy to use, better than a float valve, no wiring or power supply is required, and it takes up less space. Automatic Replenisher Water: You don't need to replenisher water frequently, it will automatically replenisher water when the water level drops to reveal a shorter tube. Advantage: The water supplement has a side hole design, which can effectively prevent air bubbles generated by back pressure. Quiet and Waterproof: The design of back pressure vibration stop + press buckle instead of sealing ring makes it quiet and waterproof. Package Includes: 1 Piece Automatic Water Replenisher Specifications: Material: ABS Outer Diameter: Approx. 33mm/1.30 inches note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.