Sears ( and most auto parts stores)usually has thin wall sockets including impact sockets. You want a six point socket and not a 12 point, as the 12 point can slip and round off your lugnut, then you you will have all kind of problems.
Without seeing your RV, most lugnuts are either 3/4" or 13/16" standard size...or 19mm or 21mm metric size.
Just for sizing purposes, see if you have a 13/16" spark plug socket in your tool collection somewhere, as they are thin wall a lot of times, and you can use it to check the lugnut size.
2011 Flagstaff 831 RLBSS
I've just ordered a chicken and an egg from Amazon.... I will keep you posted.