This product can be used to convert normal bicycles to electric bicycles, high performance. Made of environmentally friendly materials, strong and durable, easy to operate. The controller kit is suitable for installation on ordinary bicycles of 20-28 inches. It is not suitable for modification of special models and variable speed models bike. With a long service life, high durability, has fast speed and high efficiency, a good choice. Color: As Picture Shown. 8.5×6.8cm/3.3×2.7in. Type: Electric Modified Motor Accessories Motor Parameters: Rated Voltage: 36V Rated Power: 350W Flywheel Teeth: 16 Rated Speed: 330rpm Reduction Ratio: 9.78 Controller Style: Brush Controller Parameters: Rated Voltage: DC36V Rated Power: 350W Undervoltage: 20±0.5V Current: 21±1A Steering: 1-4V Suitable for 22-28 inch ordinary bicycle. Suitable for bicycles with a hub diameter of less than 36mm/1.4in. 1 Pair x Handle. 1 Pair x Brake Wire. 3 Bag of Accessory Set. This product is not suitable for bicycles that use roller coaster brakes. This product does not contain batteries or chargers. This is our electric universal bicycle kit. This kit installs sprockets on the spokes, so it fits most bicycle wheels. The motor uses a flywheel, so when the wheel rotates, the motor does not rotate like an ordinary bicycle, which can reduce drag. Please allow 1-2cm/0.4-0.8in error due to manual measurement. Thanks for your understanding. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. Our listing price includes the value of goods, packaging cost, and export. Please check with your country’s. We will reply your message within 48 hours. If you are satisfied with our service, pls. Our aim is to provide Level Customer Service, your recognition will encourage us greatly and serve you better. We strive to keep all our customers satisfy. We will do our up most to exceed your expectations in customer service, communication and dispatching of your orders.