WPL JAPAN Wide tread 5mm spacer set for metal axles

It is made by a third party.

This part is for advanced users.

This is a spacer that can widen the tread (the width where the tire is attached) by 5mm on each side, for a total of 10mm.

Depending on the shape of your wheels, the screws provided may not be long enough.
In that case, you will need to prepare screws of the appropriate length yourself.