1、Practical and Convenient: When you are on business or traveling, please use our water replenisher to avoid insufficient water supply in your sea tank, fish tank, grass tank turtle tank, etc. 2、Good Performance: Better than float valves, requires no wiring or power and takes up less space. When the water level drops to reveal the shorter pipe, the water in the bottle automatically flows into the tank due to the pressure difference. 3、Simple Operation: Easy to use, practical and fun. Simply screw the compensator onto the water bottle, then glue it to the tank and remove the positioner to adjust the spacing as needed. 4、Free Cutting: The highest water level can be defined according to the actual water pipe length. It is recommended to use more than two groups of hydrators at the same time for fish tanks over 40cm/15.7in. 5、Adjustable Clip Spacing: Clip slot fixed, stable and safe, the tank wall can bear the vertical shear force brought by the weight of the water bottle. Item Type: Aquarium Water Level Controller Material: Plastic Size: Approx. 3x3cm / 1.2x1.2in 1 x Aquarium Water Level Controller 1 x Stuck Parts