The Halo series of bearings are a high quality steel/chrome bearing with metal shields. These bearings have been tested and proven by many racers.
1/4 x 3/8 x 1/8 Halo bearing by Avid Racing Concepts is the standard bearing for 12th scale differentials and the Team Losi XXXNT clutches (these are non-flanged, standard for the Drake edition). Check your manual for the correct size for your vehicle if you are not certain.