Three CNC Fan: Increase the heat dissipation controllable fan to reduce the printer temperature when the device is working Increased Heat Sink: Redesign the drive heat sink, strengthen the drive heat dissipation capacity, and greatly improve the heat dissipation performance Output Power Supply: Increase SPI output port +3.3V power supply, external SPI sensor power supply voltage +3.3V and +5V are optional, support the motherboard to directly supply power to peripherals BLTouch V3.1: BLTouch is an auto leveling sensor for 3D Printers based on open-source.Simple, Smart, High-precision.It could work with any kinds of bed materials, such as glasses, woods, metals, and so on. This kit with 80cm extension wire