The John Guest plugs are used to plug the push-fit port of a fitting. Manufactured in gray acetal, these plugs are suitable for food, beverage, and potable liquids. They are also suitable for air and inert gases therefore can be used for CO2 and nitrogen beverage gas lines, pneumatics, vacuum as well as other applications. Features: Used to plug the push-fit port of a fitting Compatible with plastic or copper OD sized tubing Food Quality and suitable for potable liquids and pure water applications Can be used for air/pneumatic & vacuum applications Acetal body Made with lead free materials Working pressure and temperature: Max. 150 psi at 68° F Max. 100 psi at 150° F JG gray acetal is suitable for both compressed air and water (buna-n seal).