This part is no longer available
If you need the crossfader you can buy just the solder-in POT here - https://www.mpcstuff.com/akai-apc40-crossfader-potentiometer-solder-in/
If you need the PCB under the crossfader you will have to buy this compete function PCB for the unit- https://www.mpcstuff.com/pcb-assy-function-apc-40/