Post #3732277

People of a certain age will have used this thing. Same for me, but I never opened/inspected one until today. Do you know what this is? As usual, hide your #NameThatWare guess or deduction behind a CW. Because this is a rather common item per se, the correct solution needs mention what is special about this specimen and where it is commonly used. Do you also know why it was improved compared to the precious design variant?