I called them two different times and both people I spoke with said they did not have the sl350 in their data base. I ended up pulling a wheel off another sl350 I have, pulled a couple of spokes and called them back with the measurements. I too figured that someone with an sl350 would have ordered from them before but they must have had a problem with previous orders not being right and therefore requiring the measurements. Thanks for the effort, it is greatly appreciated.