This key has small trianglular spline teeth. It has a total of 12 grooves.
This key is for cars applications using American Racing lug nuts.
If you need one for a truck or SUV see part number ARA901199
Different sized tool diameters:
Trucks use a 14mm or
9/16 sized stud so the tool is larger for those applications.
American Racing 901198
Size: 12 spline