This is either a brass ankle cuff or a pencil capper depending on what size it is. Does it have any markings? Is there more than one photo view available?
If you are going to ask. You need to provide as much information as possible and the size.
It's scabbard hardware for sure, matching it to a scabbard might be fairly difficult though since so many were similar. If there's any reason for it to have been where you found it, like a military presence or a veteran, you might be able to narrow down the era and maybe find a match. cool find!