These are high-security lug nuts designed to prevent wheel and tire theft. One standard nut on each wheel is replaced with one of these locks, which can only be removed using the unique "key" (the silver cylinder in the middle of the pack). Key Specifications Part Number: 20116SU (Standard "SU" Range) Thread Size: M12 \times 1.5 Contents: 4 locking nuts and 1 matching key tool. Common Applications: Many Ford, Mazda, Volvo, and Hyundai models (though you should always verify fitment for your specific vehicle).
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