NOTE: The circuit wiring of CR-10 S4, CR-10 S5, CR 20, CR20 Pro are different from the manual, while Ender 3,Ender 3 Pro,Ender 5, CR-10 are same as the manual. 1. Use USB cable to connect CR-10 S4, CR-10 S5, CR 20, CR20 Pro with computer to flash the firmware, the ISP connector and ISP pinboard are not needed. 2. No need to plug the pinboard A to mainboard of CR-10 S4, CR-10 S5, CR 20, CR20 Pro, just insert the connectors into the mainboard D11 pins and unplug Z limit switch then insert the connectors into the Z port.Package Included: auto bed Leveling Kit x 1 Spare Plastic Probe x 1 1.2m Capricorn Bowden Tubing x 1Firmware: Please move to the Creality Official Website to download: https://creality3d.cn/products/Installation: You can refer to this video to install the BL Touch: https://www.youtube.com/watch?v=2B4qdKdqJj4Troubleshooting: If the BL touch doesn't work well. you can refer to the BL Touch website to do the troubleshootings: www.antclabs.com/wiring3If you have any questions while installing or using, please feel free to contact us. We will respond within 24 hours and offer professional technical support to you.