The auto-top-off system is easy to hang on to your aquarium sump, it can automatically fill and shut off inlet water. you make it fit a wide variety of positions and heights. Features: 1. This auto-top-off system is easy to install on to your aquarium sump. 2. Float valve for manual adjustment, no other tool, no metal screws, no corrosion. 3. Comes with a O-ring, can meet 16/12 water tube, don't leak. 4. It is suitable for the aquarium which is under 15mm thickness. The adjustable range of water level is 0.5-15cm. 5. The bracket is made of high quality material, stable and heavy enough, not easily knocked. Specification: Item Type: Aquarium Auto Water Controller Material: Acrylic + Plastic Item Color: As Pictures Shown Float Valve Size: Approx. 4 x 5.6 cm / 1.6 x 2.2 inch Package Weight: Approx. 66 g Package Include: 1 * Water Filler 3 * Accessory 1 * Bracket Note: Please allow 1-2 cm error due to manual measurement. Please make sure you do not mind before you bid.