1、[Durable Material] Stepper motor driver is made of high quality plastic material, which is durable and can be used for a long time. 2、[High Efficiency] This stepper motor driver board is noise free operation, highest efficiency and perfect motor torque. 3、[Drive Module Use Method] Remove the 3 jumper caps under the socket. The module has no subdivision setting. The step value is calculated according to 16 subdivisions. The chip uses a differential algorithm to expand 16 subdivisions to 256 subdivisions. 4、[Stable Performance] Stepper motor driver module is exquisite in workmanship, stable in performance, and can be used with confidence. 5、[Current] The current of the stepper motor controller is 4A, and the maximum current is 2A, which can meet your various needs. 1 x Driver1 x Module1 x Accessories Item Type: Stepper Motor DriverMaterial: PlasticWeight: Approx. 12g / 0.4ozAlgorithm and adjustment of module drive current 1. Driving current algorithm: i = vref* 1.9/ 2.5, the default Verf is about 0.65V, so the default current is 1.4A, and the maximum current is 2A 2. Verf measures Gnd and the voltage at the middle end of the potentiometer 3. When measuring voltage, be sure not to connect the motor, otherwise the drive will be burnt easily 4. When measuring the voltage, the power should be turned on, and don't just connect to the USB for power supply