Check valves are used to prevent liquid backflow on an airline or CO2 tubing. When using either an air pump or CO2 system, it is important to use a check valve to make sure water doesn't leak from your aquarium and into your air pump or CO2 regulator. Water or any liquids can cause damage to an air pump as well as the needle valve of a regulator
-Solid construction
-Push in fitting
-Fits any standard 3/16" airline or CO2 tubing
-Designed for aquarium use
