This is a collaboration item between Sapeur and Hamachan. It's a short-sleeved sweatshirt, size L. I purchased it at an event in Nagoya, and apparently, there were very few available, with this being the last one. I haven't had many opportunities to wear it, and it's a bit small for me, so I'm putting it up for sale. I think it's a pretty rare item, so if you're looking for one, please consider it.