This is a Giyu Tomioka rubber strap from the Demon Slayer x vivi musu collaboration. It's a strap of Giyu-san with his cool, unconcerned expression, and it's very cute. This is merchandise that was released around the beginning of the anime, so I probably bought it around 2019? I displayed it in my room for a little while, but I took good care of it, so I don't think there are any noticeable stains. However, it has been opened, so please be aware of that if you are concerned.