Kinetic Cyclone Wind Trainer Dual fans create real-to-the-road resistance while two 2.2lb flywheels offer a realistic coast down Speed-sensitive resistance from 5-1,000 watts Precision-machined roller to reduce tire wear Compatible with all bikes with 16"-29" diameter wheels (wheel diameters less than 22" OD require small wheel adapter) Unconditional lifetime warranty and lifetime crash replacement policy