It features a clutch that is supposed to prevent damage if a small rock should be in the coffee. After a short amount of use this clutch activates and the machine will no longer grind no matter how much cleaning is done
We bought one of these grinders and it stopped functioning the same day. We had better luck with the replacement, it ran for about 2 months before the same malfunction persuaded us that future investment of time or money in this product is senseless. It looks great and holds a lot of coffee beans. It is solid. It looks nice. When it worked it wasn't too noisy. No amount of the recommended cleaning according to the Chinese style English instructions would persuade these machines to grind coffee as advertized. Do yourself a favor and avoid this product.
Great Indoors allowed us to return the first of these units for another so vendor was great. Unfortunately this product does not work.