57mm Sponge Wheels White Hub - 2 1/4" (Pk2)

57mm Rounded Sponge Wheels with white hub in a pack of 2

The sponge is fairly hard / supportive rather than a soft spongey compound, ie designed for lightness and to be supportive rather than bounce.

18.5mm Thick,

Axle diameter 4mm

Weight - 7.2g (each)