everything that you may need for the maintenance of your printer.
Z PCB Board V. 4 (currently out of stock of X1 Z pcb, X1 kit doesn't have Z PCB. Genius kit is complete with Z pcb)
X PCB Board V.4
Extruder PCB Board V.4
20 Pin Ribbon Cable
30 Pin Ribbon Cable
Adhesive Tape for 20 pin & 30 pin Ribbon cable
Titan idler arm, option to get Alloy Idle arm
If you have an earlier model than the V4 (V4 has a reset button next to the screen) . On earlier V1-2-3 and some early V4 you will need to install the extruder and X axis together due to changes in the extruder board.
To check if you have the newer style heatbreak, take off the side fan and heatblock to check if it has two holes with grub screw.