Gas lost in your CO2 system can lead to a shorter life span of your CO2 cylinders. Prevent CO2 loss with a washer! A plastic CO2 washer fits between your CO2 cylinder and regulator and helps to create a good seal. A good seal ensures that you don't lose gas when carbonating or serving. These plastic CO2 washers fit Taprite brand regulators, as well as many standard-sized CO2 regulators. Keep a few on hand in case of an emergency!