Mostly little plastic clips and pieces. This includes: The connectors for the pipe, the wheels of both the hoover and the head, the opening mechanism, the wall plug, the mechanism for winding up the cable, the mechanism for adjusting the pipe length.
All pretty minor, but at some point it’s just a pain to continue using it, and we decide to retire it, for our own sanity
I think Bosch is really a mixed bag. They probably have some good ones, but they seem to also follow the plastic china vacuum route