The Revolution Series bearings are a low friction bearing with several options to help satisfy anyone's desire. What makes this bearing unique is that it has a rubber seal on one side while having a metal shield on the other. Rubber seals are great protectors against dirt but the price is that they offer a little more friction due to the tighter seal.
6x12 Flanged Revolution bearing by Avid Racing Concepts is the standard bearing for the Losi LST2 truck. Check your manual for the correct size for you vehicle if you are not certain.