My guess is those diameters belong to different sizes of shocks (the Rancho9000XLs come in different sizes for different size lifts). You should call the seller and ask them which one you need depending on the size of your lift. Or, post your lift size (or stock) here and someone might be able to help.Hi guys, Im about to buy a set of rancho rs9000xl for my 2005 wrangler. But came across to this three different diameter at the check out. 2.75" 2.38" 2.18" what is the differences? Please help.