What is it?? Military?? Badge? 1888? 1788?

[Marvin Lee]

I found this Token or Badge from Fort Boise Military Base. I think it was pat'd 1888. It looks like it was attached to something? Any help would be great. Marvin.

 

[foundinrolls]

Patent October 16, 1888

It's tough to say what it was attached to.