But which box is which?

Safety deposit sign, First Credit Union

Safety deposit boxes, First Credit Union

My local credit union has safety deposit boxes available. They even have examples out on display to help me make my decision.

The problem is that the sign lists three sizes, and there are two sample on display. So, are these two boxes a small and a medium, a small and a large, or a medium and a large.

And is the cost figure to buy the box, or an annual rent?

Yes, I know this is another example of me being too pedantic for my own good.