This 1/4" dual check valve backflow preventer with atmospheric port and strainer for carbonated beverage machines prevents the reverse flow of polluted water, such as carbon dioxide gas and carbonated water, from entering into the potable water supply due to backpressure backflow. It consists of stainless steel body construction with internal rubber components and is designed for continuous or intermittent pressure applications. It has an atmospheric port that provides visual indication of failure of the second check It is ideal for use on post-mix carbonated beverage equipment and dispensing equipment for tea and coffee. End connections are female NPT. Maximum working pressure is 150 psi (10 bar).