My brother just got something like that. I'll ask him...
edit:
He found his for about $6 at Sports Chalet (a sporting goods store), but couldn't remember the brand.
He points out that Amazon has several to offer with the search for
detachable key ring and thinks he'll opt for
this one when his breaks.
Ah. The magic word is "detachable". I couldn't think of any way to narrow the search when I was looking.
The Amazon reviews on the inexpensive ones convinced me to not waste my money, so I went with
this one. Thank you for the search fu.
tanstaafl.