What is a warehouse?
It's a joke called mechanics used on beginners. Have you ever heard of fluid from time to time?
Believe it or not, bearings were used in the Dosenberg route system in the 1920s, and bearings from the 1930s were available through LNS bearings a few years ago.
These are ball bearings on Mercedes, but the joke is the ball bearings in the input shaft of the canon valve But in reading the effect on the impeller shaft cannot be changed at both ends.