Wheel spacers?

Dumb question from the new guy: Does the spacer have a hub to carry the weight of the vehicle to the wheel? (or does the hub protrude far enough to carry the weight?)

I had a set of adapters (just spacers) on my Audi S6 (really short hubs on the German cars...like 3/4", which isn't enough). The entire weight of the vehicle sits on the lug nuts, not the hub.

Just curious...

pete