The 111mm SuperFly is our biggest wheel that features our unique Flywheel core. By definition a "SuperFly" has an OffSet (OS) bearing seat while a tradition Flywheel is symmetrical and has a CenterSet (CS) bearing seat. Every Flywheel, ReFly, and SuperFly is compatible with every Flywheel-specific drive pulley which gives you a number of great options in the Electric Skateboard (eSk8) market.These monsterous wheels are smooth as butter, roll over everything, and have a higher top speed than every other wheel in eSk8. If you have the necessary clearance you can put these on a longboard, Hamboard, street luge and roll forever.