Features: Brand new and high quality The driver integrates overvoltage and overcurrent protection. Input signal optical isolation. Bipolar constant current chopping method. DC power supply 20-50VDC (24-48VDC work is recommended). Maximum drive current 4.2A. The output current dial switch is adjustable. Low speed,zero vibration,and low noise.vHigh subdivision:2,4,8,16,32,64,128,5,10,20,25,40,50,100,125. Strong anti-interference ability,high-precision positioning can be. achieved in the harsh environment of the power grid. High reliability:power devices have enough margin,and they have been. strictly tested before leaving the factory. Specifications: Material: Plastic Note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1Set x DM542 Digital Motor Driver