I stopped by Globus the other day. There are several other stores in the front part, including Adler, a clothing store.
There is a sign in the window, helpfully proclaiming in English the services that the store offers to help its American clientele. English is spoken, VAT forms are accepted, and there are "special sizes."
In other words, there are beefier sizes since the Americans may not fit into the German sizes. It's interesting the effect that the American population has had on the Kaiserslautern area.