1. Made of high-quality material, sturdy and durable. 2. Designed with the differential pressure principle for easy place and replenishment. 3. Suitable for the small and medium fish tanks whose wall thicknesses are different, having the function of the water level adjustment. 4. Small size, convenient to store and carry, no drilling required, easy to install. 5. Custom water level (cut the length of the trachea according to the water level) 6.Low carbon noise reduction Material:plastic colour:White + Blue Package Contents: 1 Set x Fish Tank Water Add Device Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.