The price you see is the final price. Free repair or replacement in case of any quality issues. Key Features: Upgrade: Experience enhanced performance with the upgraded IRFB3077 mosfets controller. Four Riding Modes: Choose from pure electric mode, human riding model, power assistance, and push models. Enjoy the flexibility of easily switching between 4 working modes. Easy Installation: Effortlessly install this mid-drive motor into your electric bicycle using just a few tools. Remove the crankset and center shaft, then use the provided installation tools for a seamless setup. Compatibility: This kit is compatible with a wide range of bikes, including mountain bikes, road bikes, racing bikes, and more, with a bottom bracket size of 68-73/100/120mm. 48V500W/750W/1000W Mid Drive Motor Specification: Bafang Model: 500W/750W: M315 MM G340.500C/750. C; 1000W: M615 MM G320.1000. C Power: 500W/750W/1000W Voltage:48V Controller Current: 18A/24A/30A Max speed with Pedal Assistance: 40.5km/h / 47.5km/h / 53km/h No Load Speed(RPM) :126±7 /126±7 /160±10 Load Speed(RPM): 118±6 /110±6 /125±5 No-load Speed:59.7km/h / 59.7km/h / 75.6km/h Load Speed: 40.5km/h / 47.5km/h / 53km/h MAX Torque: 100N. If you choose “no battery, ” please note that the motor kit does not include a battery. Note: Gear shift sensor is not included. FAQ: Q: How do I know if this mid-drive motor will fit my bike? A: The inner diameter of the bracket should be 34-36mm. This 68mm / 100mm /120mm mid-drive motor is compatible with bikes having a bottom bracket width of 68mm-73mm / 100mm / 120mm. Pls let us know if you motor’s BB is 73mm. We will send the screws to fit 73mm bottom bracket. Q: How do I choose between brake levers and brake sensors? A: If you have hydraulic brakes or prefer to use your own brake sensors, you can choose brake sensors. They can connect directly with your brakes for seamless functionality. Q: Can I install the motor as soon as it arrives? A: Before installing the motor, please refer to the manual and follow the instructions to connect the motor and verify its normal operation. Please ensure not to disconnect any connections while the power supply is still active.