These hub bearing spacers allow for consistent and precise bearing load every time the spindle nut is tightened, regardless of the torque applied. Without a bearing spacer, bearings are typically over tightened to prevent loosening during the race. With a bearing spacer installed, you can completely tighten the spindle nut and the hub will spin free every time. Bearing spacers save time, reduce bearing temperature and greatly increase wheel free spin, putting more horsepower to the wheels. You can feel the difference by simply pushing the car!