Feature: 1. Unique designed, delicate and compact appearance. 2. With strong suction cup, can adsorbed on the wall of the cylinder or hung on the side of the cylinder. 3. Used with carbon dioxide system, equipment located where CO2 cylinder can easily observed, can used as reference to adjust the size of carbon dioxide. 4. Compact size and easy to use, can accurately measure the flowing of carbon dioxide. 5. Made of high quality ABS material, sturdy, durable and long service life. Specification: Condition: 100% Brand New Item Type: CO2 Bubble Counter Material: ABS Color: As Pictures Shown Suitable: Aquarium, Fish Tanks Effect: Connect Cylinder or Generator to Accurately Measure CO2 Flowing Using Instruction: Need Inject About Two-Thirds of the Water Before Using Weight: Approx. 24g Bottom Size(LxW): Approx. 3.5x2.1cm/1.38x0.83inch Height: Approx. 6.6cm/2.60inch Suction Cup Diameter: Approx. 2.7cm/1.06inch. Package List: 1 x CO2 Bubble Counter1 x Suction Cup