Plastic-coated wheel nut sleeves to protect the alloy wheel during assembly/disassembly. The sleeves are color-coded for quick identification of the size. 1/2 inch in sizes 17,19 and 21KraftTecos® power sleeves are manufactured from chrome-vanadium-mobyden steel. The quality standard corresponds to the norms of GGG-W660A and DIN 3121/3129 in terms of hardness, function and torque.