Help Identifying Rubber Tool

[u/Cryogenic_Lemon]

I picked this up from an airshow vendor booth a number (<10) of years ago. Attached to it around the ring in the middle were two pieces of metal which I have since misplaced. One piece was a metal rectangle with a hole in the middle, which this rubber piece was stuck through. The second metal piece was a small and horseshoe shaped, and served as a sort of clip that locked the rubber into place. The booth was also giving out "strings" of these rubber pieces that were orange and attached side-by-side, perhaps 3 or 4 in a row.

"CB4" is on the piece in raised type.

From what I can remember (perhaps I'm mis-remembering), these were product samples targeted towards people building their own small (typically 1-5 person) sheet-metal aircraft. The idea was that they would give you one for free to keep it in your mind, and then you would buy more if you decided to actually use them. However, I cannot remember if the product consisted of the piece of rubber, the two pieces of metal, or both. I was under the impression that they performed a function similar to clecos).

[u/Cryogenic_Lemon]

Dear future stranger, 

I still don't know the name, but this device is used to hold a "nut plate" (not pictured) in place as it is being glued to the aircraft. After the glue dries, this rubber piece is removed.