It is used to install 20-inch tires and is suitable for 20-inch bicycles. Please check the product size before purchasing. Note: while connecting the controller to the wires, please make sure that you connect the right colors to the controller. Otherwise, the controller may be broken. When installing, make sure that the wiring is not reversed. Otherwise, it may damage the product. Note: Not waterproof, please do not drive on rainy days Features: 1. 48V 1000W Brushless and toothless motor specification, strong and powerful. Come with powerful controller guarantee big current supply.