Application: older Peterbilt, Kenworth, Freightliner, Ford, Volvo, International, Western Star, Mack and various trailers with 1 1/2" diameter lug nuts, also it is the recommended replacement for United Pacific's rear axle covers with 1 1/2" lug nuts.
Mount: push on, turn to tighten if needed (over tighting may break the slotts)