Lug bolt?
#3
#5
to measure for proper lug bolt length on a Mercedes, it is crucial that it's done one certain way. For your car, the bolts are 12mmx1.5 in size. That size of lug bolt CANNOT protrude out of the back of the wheel more than 18mm's. 15-18mm is the proper range for that size, anything more can cause huge issues. Knowing that you have a 23mm bolt is good but you need to measure it like I said, in relation to the wheel it's going to be with. If you'd like to do that I can help you choose proper. Do not just go to eBay for lug bolts, the cost of repair to your vehicle due to the damage that lug bolts can cause is not worth it.