Kawada M300 wheel axle spacers
Kawada have released some spacers for the rear axle of their M300, and other 1/12th scales with 1/4″ (6.35mm) axles. Made from aluminium they are sold in a set of 12 with 4 of each size, 0.5mm, 1.0mm and 2.0mm widths, and help adjust the rear track width of the car as shown in the picture above.
Source: Kawada [kawadamodel.co.jp]