These ET (Spline) Tuner Nuts are a perfect fit on my aftermarket wheels and 5mm spacers, the fit and finish is superb. As you can see the enlarged part does NOT protrude through the wheel, this is critical. The small blue band on the jam nut serves as a marker to determine how many turns of thread engagement you will receive. Generally, if you have a 12mm wide stud, the wheel nuts should be screwed in at least 12mm. a thread. *** Buy them, you won't be disappointed. ***