Proxxon Micromot 60/E.
Best rotary tool I've used. Quite impressive low speed. They say 5000 rpm in lowest speed, but I suspect it is much lower than that if you reduce the output from the power supply--which is what I regularly do for drilling and painting tires...
https://youtube.com/clip/UgkxuB_mejbmcHqDUkNImyZawe7u8FiCcC30?si=n4twGDW6ZOdVMVRQ