Auto levelling sensor kit - The BL Touch is an automatic levelling sensor for 3D printers, with which the distance from the bed surface can be precisely changed and automatically adjusted. With mounting bracket and mounting kit, it is simple, smart and easy to install. Wide compatibility - This 3D touch works for Creality Ender 3 / Ender 3 V2 / Ender 3 Pro / Ender 3S / Ender 3 Max / Ender 5 / Ender 5 Pro / CR-10 with 32 bit V4.2.2 or V4.2.7 motherboard (Note: only for the above 32-bit motherboard 3D printing ). Easy firmware upgrade - Copy the firmware file to a formatted SD card without any additional files. Turn off the 3D printer and unplug the power cable. Insert the SD card and power cord and turn on the printer. Wait 10 seconds to complete the firmware update process. High precision - The standard deviation of 3D Touch is only 0.005 mm. After installing this 3D printer accessory, the printer automatically detects the height of the bed at several positions on the bed surface and automatically adjusts it so that the hotend always has the perfect distance from the bed.