Facom keys are made from silicon alloy for strength and wear resistance they undergo precise constant heat treatment that controls the hardness and ensures safe use the keys are cut not sheared to give a clean regular face and ensure a perfect fit in the screw this set contains 9 metric hex keys which are supplied in a compact wallet for easy size selection the keys are extra long with spherical heads to access hard to reach screws sizes 15 2 25 3 4 5 6 8 and 10mm