Originally Posted by gpa7pk

You're right. It's a 3/8" ID grommet available everywhere. In order to do the extenders this way you you have to install them prior to bolting the top of the shock to the shock tower. You then slide the extender shaft cover down through the drilled hole and with the extender attachment already placed on the adjustment knob, you slide the shaft up the cover as you install the shock. No change to the extender should be made untill "final" suspension adjustments are done. The white plastic clips stick-ons are just a way of holding the extenders down (rather than hitting the hatch glass).