This came on my keyring of my used 2004 3100SE.

[JJF]

Does anyone know if this is for the motorhome

[Terier]

Probably not the same thing but my dad had something like that to keep his heart medicine in. Does the end twist off?

On second thought maybe you wait for feedback before exploring.

[jonrjen]

That is half of a key ring. There is actually another half that attaches to it with another ring on the other end. The design allow you to separate the keys if needed with out having to manually turn the key around the ring to remove it.

Or at least that is what it appears to be to me.

Much like these listed on Amazon:
http://www.amazon.com/SE-Pull-Apart-...piece+key+ring

[Ford Idaho]

Given the color I think it may be a "safety key" or perhaps a disconnect key.

[F and E Damp]

x2 with jonrjen. The previous owner probably has the other half still, with his car and house keys on it.