The thermistor interface uses a combination of a capacitor and a varistor for protection, enhancing the resistance of the interface Rich extension modules, stable, easy to use, and previewable. Reserve a closed-loop drive interface to eliminate the hassle of external plug-in adapter modules Pluggable external DC5V power module Multiple fan interfaces: 1 CNC fan, 3 normally open fans Microprocessor:ARM Cortex-M3 CPU Input voltage:DC12V-DC24V 5A-15A Logic voltage:DC 3.3V WIFI module:ESP-01S Driver working mode support:SPI, UART, STEP/DIR Motor drive interface:X, Y, Z, EO, E1, five channels (each channel has a closed loop up to 256 subdivisions) Supported file format:G-code Supported machine structures:XYZ, delta, kossel, Ultimaker, corexy Note:Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use Colour:Yellow Material:Plastic Package Contents: 2 * BTT SKR 1.4 Motherboard