What is this part in spare wheel compartment?

[Katoomba]

I haven't been to the forum for a quite a while now. I'm still driving my build date Nov 2007 Mondeo Zetec. I like this car so much I just don't want to part with it. Definitely the best car I've owned in over 50 years of driving and nearly as many cars.

Anyway, today I went out the front and I've got my first flat tyre in many, many years. I prayed that the mechanics had put the wheel lock nut back in at the last service. No problems, the lock nut was there and the nuts weren't too hard to loosen. I can see at least three nail-like pieces of metal in various parts of the tyre.

Now to the point of this point: what is this part that was in spare wheel compartment alongside the jack and wheel brace? It's not mentioned in that poor photocopy-quality excuse for a manual that new Mondeo owners were given in 2008 when I bought the car.