I've had maybe a dozen of these over 40 years, I have 3 now with this new one.
And I had 6 Micrometers from 0 to 6" but those are all gone.
The dial face (clear) is gone off of 1 that I use inside the house.
The dial face is scratched up on the 2nd one in the bow shop.
Sometimes they get a piece of grit on the rack or pinion and jump timing from 0.000 and I take them appart for cleaning.
And this new one, all are Brown and Sharp (Swiss made) My dad and my Mentor would only let me buy Brown and Sharp or Starrett. Back in the 80's these 2 were the only ones
and the best to buy pretty much. Now there are all kinds
$125.00 at Amazon
Here is a good youtube on the Disassembly and Cleaning Start at 7:50