Our wheels are designed with 16mm diameter lug stud / bolt holes, and unless custom ordered otherwise, are specified to use a 60 degree conical seat lug type. Many, if not most, of our wheels are also specified to use a small diameter, splined lug nut / bolt type. 'Splined' simply means that an additional tool that slides over the outside of the nut / bolt instead of a traditional socket is used to install and remove the lug nuts / bolts.
To ensure a proper fit and maintain the wheel warranty we recommend using Gorilla Automotive small diameter splined lugs. The conical taper is perfect and the socket works well with most wheel designs. You can find Gorilla Automotive products on-line or at most local wheel & tire shops. Older vintage wheels used a mag lug with washer...if your lug hole appears flat with no taper please visit your local dealer to purchase the proper lug nuts.