Yes the shims are only 3mm,your better off going 15mm,mvtech do 15mm,good quality & only £60,the prob with 10mm on hubcentric is the bolt holding them on can only be 10mm or smaller(depth).thats lots of load through such a small nut,ive played about with spacers on standard rays & i found the best set up is 15mm fronts&20mm back or 15mm all round,anything bigger detracts the quality of the drive imo though does look good.