The casters are very high quality and fitted straight onto my classic wheel stand and rear seat frame. The locking mechanism is robust and stops the frame from moving. The whole rig is very easy to manoeuvre, even on my carpet. I suffer from arthritis, so the casters mean I can put my rig into position, without days of pain afterwards.
The casters were dispatched quickly and arrived the following day, although I was not happy with UPS. They claimed no one was in (when there was), so delivered ...