Correct. There is a big difference between the cheapy shim style spacers (although, several companies make quality versions of this style, but they are typically hub centric and include the installation of longer wheel studs) and the bolt on style that has become popular during the past 10 years or so.
New to the forum? Ignore everything 99_wj_QD says.
His:'00 WJ, 4.7 Limited, stock
Daily Driver: '05 SRT4, Stock turbo, 252 WHP, 321 WTQ
Hers: '03 WJ, 4.7 V8, Kolak Exhaust, IRO 3", Bilsteins, JKS TB, KOR TB Bushings, 32" Cooper ATP's