Important NOTE:This item is for the bike that uses the hub diameter less than 36mm. This item does not include battery or charger. This is our newest kit for electric common bike, this kit mounts the sprocket on the wheel spokes, so it fits most of bicycle wheel. Motor use freewheel so when wheel rotating, the motor will not rotate, just like a normal bike, this can reduce resistance. The thumb kit includes:1.1x 250W 24V brush motor with freewheel2. 1x Customized sprocket, components4. 1x Wuxing thumb throttle (with battery indicator, switch button). Welcome(?’?’?). This Item Is for the Bike That Uses the Hub Diameter less than 36mm. This Item Doesn’t Include Battery or Charger. This Is Our Newest Kit for Electric Common Bike, This Kit Mounts the Sprocket on the Wheel Spokes, so It Fits Most of Bicycle Wheel. Motor Use Freewheel so When Wheel Rotating, the Motor Will Not Rotate, Just like a Normal Bike, This Can Reduce Resistance. The Thumb Kit Includes. 1x 250w 24v Brush Motor with Freewheel. 1x Customized Sprocket & Components. 1x Mounting Plate + Bolts. 1x Wuxing Thumb Throttle (with Battery Indicator & Switch Button). During installation, it is necessary to adjust the angle to ensure that the front and rear wheels are in a straight line. If the angle is not correct, it can be adjusted by adding or removing shims under the mounting plate at the axle position. If the front and rear wheels are not in a straight line, the chain will tilt to one side. This causes the force to tilt to one side all the time when the flywheel rotates, making it easy for the flywheel to be damaged. 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.