Why choose the little motor- TSDZ2B Mid drive motor? Fits 95% of standard bike frames with 68-73mm bottom bracket built in torque and cadence sensor- this results in much smoother acceleration than any cadence sensor mid drive motor. Easy to install. Kit includes all installation parts and tools. The motor has an extra support mount - resulting in a much more reliable install. 80Nm of torque The TSDZ2B Mid Drive Motor - Torque Sensing Pedal Assist: The harder you pedal - the harder the motor works with you. 4 levels of assist provide smoothly integrated power ranging from +36-300%, allowing you to conquer virtually any   hill with ease. These kits retrofit most bicycles by replacing the bottom bracket & crank set assembly - to utilize the existing drivetrain & gears for maximum efficiency. The VLCD-5 Display - w/ Throttle & E-brakes: The VLCD-5 is a larger, center mounted display with ports and wiring for a throttle, e-brakes, and an external handlebar mounted button panel. It also houses a USB port for charging your mobile device (installation/use of the throttle, e-brakes, and/or external button panel is optional). What improvements have been made when comparing the new TSDZ2B to the old version? The upgraded TSDZ2B now features an all-in-one reduction gear kit, which cannot be separated, making it more robust and stable. Additionally, the one-way needle bearing has been replaced with an all-in-one nylon gear in the new TSDZ2B version, providing increased torque with an external clutch. Moreover, the new bi-directional freewheeling clutch enables you to ride your bike as a regular bicycle when the power is depleted. Specifications: Model        TSDZ2B Rated Power     500W Efficiency (%)     ≥80 Reduction Ratio     41 Wheel Size (Inch)     Optional Rated Voltage (DCV)     48V Max Torque (N.m)     80 Weight (kg)     3.5 n0(Rpm)     66/94 Power Assist Ratio     36%~300% Pedal Sensor     Speed and Torque Integrated Shaft Standard     JIS Noise Grade (dB)     <55 Throttle     Thumb E-Brake     Yes Light Drive Capacity (DCV/W)     6/3 IP Level / Salt Spray Test     65/96 Certification     CE/RoHS/EN 15194 Bike Recommendation     E-CITY / E-TOUR Battery Specs: 48v Battery Nominal Voltage: 48V Rated Capacity: 15Ah / 20Ah / 28.8Ah Watt Hours: 480Wh Configuration: 13S4P Battery Cell: A-grade 18650 2500mah   Max Continuous Charge Current: 3A Max Constant Discharge Current: 30A( BMS) Charge Cut-off Voltage: 54.6V Discharge Cut-off Voltage: 36.4V Battery Weight: 3.9kg Charger included Features: Universal compatibility: Fits almost bikes in market with 68-73mm bottom bracket,Free Gift Wrench. Torque and cadence sensor: Much smoother and better, as it can match your power, not just turn on or off when you do Installation & Mode: Easily installation by the installation video and the instruction manual we provided;Three riding Mode (E-bike & Pedal Assisted bicycle, Pedaling bicycle, Pure Power bicycle) for you to choose, you can choose the E-bike to enjoy a long time travel, and also exercise. Light and smart: 30% lighter than a Bafang motor for almost the same power output . Package included: 1 x Mid Central Motor 1 x VLCD-5 Meter 1 x Cranks 1 x Speed Sensor 1 x Gear Button 1 x Wrench 1 x Throttle 1 x Manual 1 x 48v 15Ah / 20Ah / 28.8Ah Battery 1 x Charger  Note : 48V 500W Is not road legal ebike power ,we only recommend off road use !! Warranty : 12 Months replacement warranty for motor and battery, under normal household use battery life ≥ 800 cycles Professional  installation recommended The max speed will be between 30km/h to 40km/h depending on bike's gear ratio ,smaller teeth sprocket will make bike go faster.