Cup port: width 2.1 "High: 2.45" / 2.6 "<br> Great decoration for shrimp or planted tanks <br> Can be used for growing special plant or used for aquascaping <br> <br> Warm Reminder:... < br> - Install on smooth surface only.To extrude air quickly, you could put one drop of water inside the suction cup and extrude with water <br> -.. Fixed glue is required on unflatness surface <br> <br> In order to strengthen the suction force of the suction cup, we distribute two transparent double-sided adhesive stickers for each glass, <br>especially suitable for glass, mirror and ceramic tile installation on smooth surfaces. <br> Please keep the suction cup and the contact surface clean and sticky before use. <br> Then press for more than 5 seconds before using.