High-precision stepping motor - Ensure the accurate transmission of the strips, and the imported stepper motor can control the length of the lining strips Imported photoelectric sensor control - high power signal amplifcation sensor trigger signal, to ensure that the device is synchronized with the machine needle and thread trim- ming mechanism. Adopting a unique weighing rod principle device - the rod winding mechanism is designed with reference to the weighing rod principle to ensure that the rods are sent and received synchronously and avoid the rods from breaking