The key ring has 4 or 5 keys on it.
Two that stand out are: 1 VW van key (the biggest key, size of a car key). Roundish head, with the letters "VW" on it. 1 small key for a mini padlock.
Plus, a gas cap key, and I think a house key.
Attached (unless it fell off) to a flat, black-colored roundish flashlight -- about the size of a thick quarter (maybe 4 quarters thick).
We stayed in VW Bus Camp, but have no idea where at Burning Man they vanished.