I'm not exactly sure what you would call it. It was a circle of leather about three and half inches across that I was given in art class when I about eight years old I think. My art teacher punched out the hole at the top, then I used a hammer and some letters to press "R DAY" with a star underneath, and some patterning along the edges, so everyone would know that this was
MY key chain. Then I dyed it light brown, waited it to dry out and hung my keys off it for the next thirty-five years. Over the years the leather got worn down and also got soaked and dried so many times it was dark and cracked all over so you couldn't really see the letters anymore, but I kept it just because with that big leather disk hanging off it, there was no way I'd ever really lose my keys.
Until yesterday that is, when the leather broke at the hole where the keyring was inserted, while I was pulling it out of my pocket to unlock the mailbox. There's no real point in trying to punch a new hole for it, and it can't be repaired, so I'm going to have to either throw it out, or find a place of honor for it in my junk drawer.
Salutes.