9V-42V DC power supply, H-bridge bipolar constant current drive. The maximum current can be up to 4A and 8 output currents can be . 6 subdivision modes of up to 32 subdivisions can be ,and can be used for high subdivision purposes. Energy-saving semi-automatic current lock function with built-in over-temperature protection and over-current protection. High speed optoelectronic isolation signal input. Single-chip PWM bipolar sinusoidal chopper ensures low vibration and high efficiency. input signal high speed photoelectric isolation common-anodestandard single pulse interface offline to maintain the function semi closed enclosure can be adapted to a more stringent environment Colour: black Material: ABS Package Contents: 1 x Stepper Motor Driver Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.