Using 32-bit high-speed ARM chip as the main control chip STM32F407, the main frequency is up to 168MHz, compared with the mega 2560 (16MHZ), the data processing capacity is faster; Using high-quality MOSFET tube, the heat dissipation effect is better; Using a dedicated power supply, the chip supports 12-24V power input, the same system power supply can reduce the hot bed current to 1/4, which effectively solves the problem of MOS tube heating; Industrial-grade chipset, printing is more accurate and faster, with over-current protection, overload protection, over-temperature protection, over-temperature alarm and other safety functions (automatically turn off the heating switch); Support offline upgrade function, copy the upgrade file to the memory card, insert a 3D printer to complete the program upgrade; Specifications: Input Voltage: 8-35V Motor Driver: TMC2208 Sensor Type: 100K NTC Thermal Resistance Firmware Update: Support Offline Upgrade Function Connection Mode: Online/Offline Printing Resume Printing: Yes Filament Detection: Yes Style:A Et4+ Motherboard Colour:black Material:PCB Size:15 x 14 x 1.5cm Package Contents: 1 * ET4+ motherboard Only the above package content, other products are not included. Note: Light shooting 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.