Description: 【Product】: This Aquarium CO2 Bubble Counter with Check Valves is designed specifically for CO2 Regulator Systems, serving as an essential tool to ensure a aquatic environment.(Note that this does not completely stop the reversal) 【with Check Valves】: CO2 Bubble Counter features a built in check valves that effectively prevents liquid from flowing back when the pressure changes, ensuring that the water plant table and CO2 bottle are not damaged. 【Detachable】: The CO2 Bubble Counter is detachable, making it easy to clean and maintain. 【Clear Tube】: Clear tube designs of the bubble counter allows for easy counting and measureing of CO2 bubbles, providing great control over CO2 output. 【Easy to Use】: This Aquarium accessory is easy to install and operate, making it a user friendly addition to any CO2 Regulator System. Size Chart: 7.8cmx2cm/3.07inchx0.79inch Package Includes: 1 CO2 Bubble Counter Note: Please allow slightly errors due to manual measurement and different monitors.