Aided by the launch of the F-05 Front Multi-Roller device (15808), DR-EVO Multi-Mount back Body (15341) and DR 11mm Aluminum Passing Roller w/ Built-In Ball Bearing (15342) how many ball bearing related option components for Dangun Racers have actually increased rapidly. In order to offer more ball bearing choices, Tamiya now releases 2 types of ball bearings especially for Dangun Racers. Each set comes with 2 bearings.