Listing these for parts or not working, one of the indicator Rings is missing, and I may yet still have it and if I do I will include it with these. I believe it's one for a burner. These need to be cleaned. These are not new and show signs of use and age. There is no metal sleeve for the back of them and I don't believe that ever was. Please use the pictures to help determine the condition of these items. I am selling these items as is.