Powerful operating system ensures that vehicle control, motor control and user-side programs run simultaneously. Advanced pulse width modulation technology ensures that the electricity is used efficiently and reduces the loss of motor energy consumption and torque conversion. Built-in electricity status and timer function. Always believe we can solve problems by communication if there are any problems. And if a return is the last solution, the product must be intact and the same as you receive, also should be within 30 days after you receive your package. Thank you and have a nice day.