These are a front anodized aluminum wheel hub. We offer them in many sizes, colors, and lengths to fit your needs. These hubs are meant to slide onto a front spindle. They come with bearings pre-installed. They are available for a 25mm and 17mm spindle. They have 3, 8mm wheel studs pre-installed that are 3 on 58. 3 on 58 stands for 3 wheel studs at 58mm apart. 58mm is measured from the outside of one stud to the outside of another.