M1 Dual Durometer Aggressive Rollen, 4-pack

M1 Dual Durometer Wheel features M1's New Urethane core material with a higher heat tolerance, as well as being about 7 times as strong as to old cores.
The Dual Duro-meter features a larger core than our standard wheel to give increased speed and impact tolerance.

M1 Pro Series Purple Urethane, 59MM Hard Urethane.

Only exist in the hardness "Hard".