I was repairing the chain, it was necessary to update the soldering on the links, which came off and cleaned with ultrasound. In fact, it seems to have been cleaned, but there is a white plaque on the chain where soldering was done. As a result, I didn't immediately notice what was being cleaned or not. The price is also not cheap, I used to carry out repairs in another workshop and it was cheaper there, but it closed. Be careful when you pick it up.