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 ControllerMaterial: Acrylic + Plastic Item Color: As Pictures ShownFloat Valve Size: Approx. 4 x 5.6 cm / 1.6 x 2.2 inchPackage Weight: Approx. 66 g Package Include: 1 * Water Filler3 * Accessory1 * BracketNote:Please allow 1-2 cm error due to manual measurement. Please make sure you do not mind before you bid..