The MW integral aluminum lug nuts are for applications where very ounce of weight is critical. The part is produced from 7075-T6 aluminum alloy with a durable anodized hard coat finish. The integral aluminum washer snaps on to the nut and spins freely, but will not separate from the nut, preventing accidental loss. 3/8" grip, threads relieved 3/8" on wheel side of nut. The nut has a fixed counter bore depth that is equivalent to using the standard nut/washers combinations in the 3/8" thickness. Sold each. Installation - Service instructions can be found on Service Bulletin #0039.