We left as found. Comes with the booklet that shows you how it works. Great conversation piece and it works. The base comes off, has a spindle that t spring fits on. Then there is a center mount. Check it out. My Dad was an automobile mechanic in the 1950s and 60s and he used this in the Ford Garage to balance tires. Too Cool! See the photos for details. Comes with the original booklet that shows how to use it.