This pneumatic simmering ring seals the rotating shaft where it passes through the pneumatic system housing, preventing air leakage and maintaining system pressure. It sits in the bore between the shaft and the housing, with its sealing lip contacting the shaft surface. A worn or hardened ring allows air loss, which reduces actuator force and causes sluggish implement response. Corteco produces this ring to the original seal geometry, matching the housing bore tolerance and shaft contact width so no adapter or shim is needed during installation. Lubricate the sealing lip before assembly and press the ring squarely into the bore to avoid lip distortion.