[Scope] This control value is applicable to carbon dioxide supply systems in aquariums, aquariums, etc. [size]39*8mm [Maintain service life] This one-way check valve can prevent water from being poured into the aquarium due to restoration, and maintain the function and service life of the carbon dioxide bottle. carbon. [Anti-corrosion] When used in an ozone generator, it can prevent ozone from flowing back to the air pump and corroding the propeller. [Effective and flexible] Our aquarium control value can protect the power head from water backflow due to power interruption. [High quality material] It is made of stainless steel and is very durable.