You were looking at a Dayton2E816. This item is brand new. I’ve taken it out of the box to show you exactly what you’re bidding on. You can see that the item is wrapped up and ready to go. I have looked this item over carefully, and I believe that the knob is on the inside of the thermostat. I don’t want to take it apart, but I am making note of it that there is a piece of plastic on the inside of this unit that looks like it is holding the knob please look at all pictures. I do consider my pictures part of my description . Thank you.