McGard UHS security bolt set (4 bolts + 1 key). 14x1.5 thread. R14 ball cone. Length to cone 37.1 mm. Key 19 mm. Chuck diam 29 mm. To increase security, the UHS series bolt head has a rotating ring. which makes it extremely difficult to open them without a special key. The UHS series meets Thachams 4-level security category. Do not use a compressed air wrench to tighten the security bolts! Each package comes with an ID number. based on which you can order a spare key!