Features: CNC Board: 1. PWM spindle and direction pin. 2. 2 * The end baffles of each axis, a total of 6. 3. Coolant activation. Compact design. 4. Use a detachable A4988 or DRV8825 compatible stepper drive. 5. Please note that this is an unassembled kit that requires basic soldering techniques. 6. The stepper motor can be connected or soldered in place using a 4-pin molex connector. 7. Run on 12-36V DC. Currently only the DRV8825 driver can handle voltages up to 36V, so consider the operating voltage when powering the board. DRV8825 Stepper Motor Driver: 1. Applicable to 2.5A stepper motor drive below 8.2V~45V. 2. Six different step resolutions: full, half, 1 / 4, 1 / 8, 1 / 16, 1 / 32. 3. Simple steps and direction control interface. 4. The adjustable potentiometer adjusts the maximum output current to increase the step rate. 5. Automatic current decay mode detection/selection. 6. Thermal shutdown circuit, undervoltage lockout, cross current protection. 7. Ground short circuit protection and load short circuit protection. Specifications: Model: CNC Shield Expansion Board+drv8825 Stepper Motor Driver+Heat Sink Suitable: for Arduino V3 Engrave Type: 3D Printer Accessories Package List: 1 * CNC Shielding Board 4 * DRV8825 stepper motor driver 4 * Mini radiator