The hardware holding your wheels to your car is an often overlooked step when installing new rims. Most aftermarket wheels require different wheel nuts / bolts than what was used on the original equipment wheels. Wheel nuts and bolts have many different seats (where the nut touches the wheel). The 3 most common are acorn seat (conical), ball seat (radius), and mag shank seat. These differences along with different lengths and diameters makes hardware very confusing. Always check with the people who supplied your wheels for the correct mounting hardware before trying to install them on your vehicle.