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. About the battery: The power and voltage of the battery. 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. Brushless and toothless motor. Specification, strong and powerful. Come with powerful controller guarantee big current supply. Suitable for both V brake and Disc brake. The maximum speed of the motor will be 50km/h. The open size of the front fork is 100mm. The size of the rim is 20(Suitable for 20 inch bike). Crank speed sensor for pedal assist. Condition: 100% Brand New. Optional Type: Front Motor. Motor Specification: 48V 1000W. Front fork open size: Approx. 100mm / 3.9in. Brake: V brake/disc brake. Assist: 5 magnetic point assist sensor. Brake Lever: Power cut-off brake lever. Wiring Mode: Waterproof wire for outgoing motor, common wiring for other. 1 Electronic power brake. It is used to install 20-inch tires and is suitable for 20-inch bicycles. Please check the product size before purchasing. France, Germany, spain, Italy. Feedback is very important to us. It is impossible to address issues if we do not know about them! Please keep the original box or packaging within 15days since item received. Your satisfaction is our ultimate goal. We work hard to earn your trust and future business. A If you receive a defective item, you may return it or ask for a discount. Due to time zones, our reply to your questions may not be immediately. If it’s non-workdays, please kindly be patient and wait till Monday. Front fork open size. 5 magnetic point assist sensor. Power cut-off brake lever. Waterproof wire for outgoing motor, common wiring for other.