Atom wheels are made out of the highest quality Urethane. Unlike other wheel manufacturers, we ONLY make wheels. We are dedicated and focused on making the best wheels for all types of skating, especially roller derby! Our in depth R&D in other fields of skating gives us profound knowledge about performance urethanes. The same urethane used in derby by Atom Wheels has dominated the race industry since 1989! Atom is the official wheel of the WFTDA.