Features: brand new and high quality The maximum step pulse frequency is 100 KHz, supports 4-axis linkage, and can be connected to four stepper motor drives or drives. Support automatic probe tool, emergency input, limit switch, connect electronic hand wheel, with status indicator LED light. It is necessary to use an external 24V for DC power supply to isolate the USB and external ports to make the system more stable. With 0-10V output port, you can use mach3 software to control the spindle-motor speed. 4 general-purpose isolation relay drive output interfaces, which can drive 4 relays to control spindle-start, forward and reverse rotation, pumps and other devices. Package Includes: 1x Breakout Board Specifications: Material: ABS Size: Approx. 77.5x81.5mm/3.05x3.21inch Output Current: 1.4A Minimum, 5.6A Maximum Input Power Supply Voltage: 20v Minimum, 50v Maximum Step Pulse Frequency: 200khz Insulation Resistance: 500m Temperature: 0~+50C Humidity: 40~90% Vibration: 10~55hz/0.15mm Storage Temperature: -20~65C note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.