it is the actual spacer when they put the spacers on my new rims to make them fit over the caliper it sticks out past the center hub so no matter how tight you lock down the lug nuts the spacer is still going to move ever so slightly causing the out of balance wobble in the steering wheel........they are having some made but i thought there was somewhere they might be able to pick them up without having to have them made..........being that my math skill suck im not sure on the millimeter but i know they are quarter inch thick......i never did well in metric class as a child..............the rim doesnt have that little lip to catch on,,,on the center hub....it is very hard to explain but very easy to show....i told them to check with i think it is H&R or HR .......but have not gotten a response yet .........thanks for the replys though.