Air actuated exhaust brake mounted inline in the exhaust system. Air source and heavy duty exhaust valve springs must be installed prior to install of this exhaust brake. If required order 1030122 Air Compressor Kit and 1030060 Heavy Duty Exhaust Valve Spring Kit. Other exhaust brakes available are a turbo mount/air actuated kit (p/n# 2023123), turbo mount/vacuum actuated kit (p/n# 2033123) and a remote mount/vacuum kit (p/n# 1033121).