1.Speed 80km/h with high torque,convert on mountain bike. 2.Double hall sensor, make sure the quality 3.48-72v smart controller, work on different voltage 4.Brushless gearless design, advantage on speed with long warranty and working life 5.MTX39 rim, strong and hard for the 1.9-3.0 tire 6.2 years warranty, 5 years working life 7.3000w electric bike conversion kit 29 72v