I had the unit in heavy use because I do not for the first time, the spring of the "patented" Schnellkuplungsmechanismus fell just four weeks out. The is designed to prevent the plate accidentally cuts off. I then reinserted. Two weeks later, the spring then was just gone. The unit is still working, the oh-so-great mechanism is simply no longer doubly secured, but only just. Had no desire therefore to send the thing back.