I have one too. My mother was hard of hearing and got one of those with a volumn control, which I have as an extension now. She worked for the phone company back then, so did not have to pay extra for it. With the old Bell System, if you had any disability, too bad, so sad, we are going to charge you extra for what you need to communicate. At least that was finally changed for the better. That old black phone still has my parents same number in the center of the dial.