Mukluks. I noticed he'd worn a hole at one of the big toes in these slipper socks that I made for his birthday 4 years ago. He has worn these slippers a lot, so I wasn't surprised that they might start falling apart. I hadn't investigated carefully, though, until I grabbed them today to photograph. I am very happy to report that the knitting is completely intact, it is only the yarn used to secure the knitting to the sole that has worn through. Easy fix!
Four More Years!