TAMIYA
Mini 4WD upgrade parts
Machined aluminum roller with a diameter of 13 mm that expands the range of roller settings.
A 520 bearing is embedded in the main body to achieve smooth rotation.
There is no rubber or plastic ring around the outer circumference of the roller, so it can be attached to the front or back.
The key point is that it is about half as light as a 13mm ball bearing for rollers, at about 1.7g for two pieces.