Shopsmith air system air compressor attachment for a shopsmith. These were the ones made in the 90's by Campbell Hausfeld.  Unit seems good. Feels like air  compression when turning shaft. However these are easy to repair if the rubber had degraded. Seems barely used . I removed it from the mount to clean and get better pictures and picture of the serial number. Some pictures were taken with the flash so you can see the condition. It will be shipped unmounted from the mount for safer travels. Mount is included