Utilizing the release of the F-05 Front Multi-Roller device (15808), DR-EVO Multi-Mount back Body (15341) and DR 11mm Aluminum Passing Roller w/ integrated Ball Bearing (15342) how many ball bearing associated option components for Dangun Racers have increased rapidly. In order to provide more ball bearing options, Tamiya now releases 2 types of ball bearings particularly for Dangun Racers. Each set is sold with 2 bearings.