describe: 1. Support 4-axis linkage, can connect 4 stepper motor drives or servo drives; 2. The maximum step pulse frequency is 100KHz, suitable for servo or stepper motors; 3. Support automatic detection tools 4. Support emergency input 5. Support limit switch 6. Support connection of electronic handwheel 7. Need to use an external 24V DC power supply to isolate the USB and external ports to make the system more stable 8. With 0-10V output port, you can use mach3 software to control the speed of the spindle motor. 9. 4-way universal input, can be connected to limit switch, emergency stop switch, probe switch, zero return and other devices 10. 4 universal isolated relay drive output interfaces, which can drive 4 relays to control the spindle start, forward and reverse rotation, water pump and other devices 11. 1 status LED to indicate the connection status on the board Specification: 100% brand new Color as shown Size: 8x7.7cm/3.15x3.03inch Quantity: 1 set Package Includes: 1 x USB CNC Controller Card 1 x USB cable 1 x CD notes: 1. Due to manual measurement, please allow 1-3mm error. 2. Due to the difference of different monitors, the picture may not reflect the actual color of the item. Thanks! ⭐Excellent product quality with a long service life ⭐Welcome your inquiry at any time, happy to answer any questions ⭐Good after-sales service, please feel free to contact us if you have any questions