The Edelbrock/Russell Speed Bleeder replaces the stock bleeder valve in your caliper/wheel cylinder with a spring-loaded one-way ball and check valve design. This unique design opens to allow the old fluid and air out, and then closes automatically between pumps to prevent the old fluid and air from re-entering the line. Its thread sealing system displaces air and moisture during thread engagement as well as eliminates air from being pulled back into the system during bleeding. The installation is a one-person task and the unique double-patent design ensures authenticity. A dust protection cap is standard with each bleeder screw.