Kit includes all wheel bearings for both front and rear wheels - 2 front, and 3 rear. Fits standard OEM wheels only, not for aftermarket applications (available separately, please ask!). Worldwide Bearing Hybrid Ceramic wheel bearings reduce friction by up to 40% - this reduces rolling resistance, and puts more power to the pavement. Ceramic bearings also offer less rotational weight, which again aids in acceleration. These sealed bearings are maintenance free, and are pre-filled with Mobil lightweight aerospace grade lube. Overall, you can expect three to five times the service life from Worldwide Bearings Hybrid Ceramic, and they include a two year warranty.