For ease of purchasing, the Wheel Bearings are listed here under their serial numbers with their sizes for comparison and below that section, by make and model, for front or rear (for those who are not aware of the bearing ref's or sizes).
The prefix 2RS against the serial number denotes that it has a rubber seal on both sides of the bearing, ideal for wheel bearings where water and dirt need to be kept out.
At the lower half of this page, you will find the Steering Head Race Bearing Sets for both Mx, Enduro and Trail.