Quak,
It is an option that can be built in to your GT hull by the factory. It can be used in any way you can imagine using a 2" hitch receiver, but the more commonly seen applications are as a winch mount or to hold an extra cargo platform (like the ones you see hanging off the
back of SUV's and cars). I just saw a hitch mounted market-size umbrella and am thinking about buying one for giggles, as I have ordered the hitch receiver on my new GT.
http://www.sierratradingpost.com/pro...x?baseno=98340