[Integrated heat sink and built-in PWM speed control] - Allows for easy adjustment of motor speed without having to adjust the power supply. [1/128 micro-step resolution] - Provides incredibly precise control of the motor, making it perfect for CNC machines, 3D printers, and other applications where precise movement is necessary. [Anti-resonance and torque smoothing technology] - Prevents the motor from vibrating and eliminates noise, allowing the motor to run at higher speeds without losing torque. [Overvoltage, overcurrent and overheat protection circuitry] - Ensures that the driver is safe and reliable. [Delivers up to 1.0-4.2A and 20-50VDC to the motor] - Provides the motor with the power it needs to operate efficiently.compatible With Nema 17 and 23 Stepper Motor. Material: ABS colour: black Package Contents: 1 x DM542T CNC Stepper Motor Driver Only the above package content, other products are not included. Note: Light reflection 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.