These studs have a mushroom shaped base, steel body and carbide tipped protrusion. At our warehouse we drill the holes, we inject bonding glue and then use a unique machine to insert each stud. This same process is used in Europe. It is very time consuming.
Beware of the imitations!
This tire is a Trelleborg XT-454. This studding pattern is the COMPETITION model - we skip a stud dimple on a main lug in the center of the tire. This was commonly asked for to lessen traction just a bit and to put less stress on the lugs. It also saves unsprung weight and cost.