1Power Off Memory: Comes with power off memory function, the motor controller adds more convenience to the operation. 2Adjustable Speed: From 0.1 RPM to 999 RPM, the rotational speed is free and easy to adjust to meet your working needs. 3Various Function: The step motor driver also enables simple adjustment on angle, distance and delay, very practical. 4Safe Application: Ensuring reliable and efficient performance, the control module suits for 42 and 57 step motors. 5Easy Maintenance: Digital display makes the adjusting much easier, and the installation and maintenance are very easy. Item Type: Step Motor Controller Type: YF-19 Power Supply Range: DC 8V-24V universal. Speed Range: 0.1-999 RPM 1 x Step Motor Controller Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.