The Minoura Magturbo-500 Series tire drive Rear Wheel Trainer. Beginner-level 500 gram flywheel. Fits 24" to 700c wheels, and folds flat for storage. Extra powerful magnet increases high range of resistance by 23%. Mag-500 Series: beginner level 500 gram flywheel. Works only with smooth tires. Skewer and skewer adapter included. Dial and Remote include seven magnetic resistance levels. Fits 24" to 700c wheels, folds flat for storage. Extra powerful magnet increases high range of resistance by 23%. Quieter, improved heat dissipation. Team Cyclist is an authorized Minoura dealer and will honor all manufacturer warranties.