If they are the same as GRP-A which I beleive they are you will need either grp-a/4 studs or you can just buy a set of conversion nuts like these:-


The conversion nuts are the better option as you bascially just fit them the only down side is you can't get a locking nut

If you go for the stud conversion they are bigger studs in terms of width so need to replace the studs in your hubs with grpa/4 studs plus your have to have your brakes discs/bells drilled out to the same size spec.. shit loads of hassle, plus side is you can have a locking nut

Stud looks like this