Description: 【Side Hole Design】: The Water Level Controller features a unique side hole design that effectively prevents the formation of bubbles due to back pressure. 【Adjustable Slot Spacing】: This automatic water replenisher allows you to adjust the slot spacing according to your needs, providing flexibility and convenience. 【Automatic Water Replenishment】: Ideal for maintaining the water level in your fish tank, this Automatic Water Level Controller automatically adds water when needed, ensuring a healthy environment for your aquatic pets. 【Easy to install】Fish Tank Water Replenisher Accurate water level controller, easy installation, practical to use. 【Multipurpose】The Fish tank filler is suitable for fish tank and aquarium. The water level controller is small in size and does not occupy the fish tank space. Size Chart: 4.5cmx3.8cmx6.5cm/1.77inchx1.50inchx2.56inch Package Includes: 1 Fish tank filler with tube(4 Pack) Note: Please allow slightly errors due to manual measurement and different adult.