The end of the Link bolt is 10MM. Use a socket and box end wrench to tighten nut and loosen nut at neutreal position works good for proper assembly. On a side note I have removed the vanity foglight plate from the driverside front fender added alittle paint some Gaffers tape to deflect the air towards the air intake inside the fender and block some engine heat. Major cooler air intake! Before at the end of a trip the air filter box was warm or hot, not now and cold at night. "Cold air intake" for free! Party on.