Hub Rings?

I went to go and look for some rims for my 94 integra and the guy at the shop said that you would also need to buy hub rings if you got aftermarket rims, along with the normal rims and tires. He said that the car would shake if you didn't buy them. I had never heard of that, i just thought you bolted it on and it was fine. So whats the deal with the hub rings? :wtf:

it really depends on the type of aftermarket rims you plan on getting. now for stock rims, i would tell him he is full of s^%#. but here is a web site that describes them in better detail http://justforwheels.com/index.jsp?cat=hubcentric&sub=how&track=GHR