Locking nylon-insert nuts to replace the ones on the front upper control arms and on the rear radius arm pivot pins. When Nyloc nuts are used, the original plain nut and lock washer will be replaced. They are included in the respective kits for these applications, but if you don't need the full kit, we can supply the correct locking nuts as needed. Sold each. Ref: FNZ508, FNZ0508.