These are Double Aluminum Rollers that are used for Mini 4WD racing machines. They are used to tune the chassis to achieve better stability and higher cornering speeds. This particular version is a limited-edition variant which is lightweight compared to other double rollers.
With the 9mm roller in the lower position and the 8mm roller in the upper position, it improves stability greatly and also enhances cornering ability. Friction is minimal when the aluminum rollers make contact with the course track walls, allowing for faster speeds.
• Double Aluminum Rollers (Red) x2
• 520 Ball Bearings x4
• Nearly 20% lighter than standard Double Aluminum Rollers (13-12mm).
• 520 ball bearings provide silky smooth movement.
• Small parts for attachment included.
• Compatible with Mini 4WD and Mini 4WD PRO cars.