The limited edition of 150 pieces sinn watch 901 leather the limited edition of 150 pieces chronograph 901 is ample proof of our expertise in the field of case making we have collaborated closely with sug in glashtte which produces the technologically sophisticated cases for our company what is special about this case is the ability to finely adjust the lugs allowing users to extend or shorten the bracelet length the mechanism is built into the case and permits the bracelet to be altere