The SD card for the PAC can be ordered through a local Parker distributor:
Parker p/n 33-026611-01
After ordering a new SD card you will need to configure the SD card for use in the PAC. You can download the appropriate Flashback Utility from the PAC product page as well as the Hardware User Guide which contains instructions on using the Flashback Utility.
Alternatively, here is the vendor information for the p/n 33-026611-01 if you wish to source this SD card yourself:
Vendor Information: Centon p/n C4-CM-SDC4-2G-003C
It is strongly recommended that the Parker SD card be used as this card has been tested and proven to work correctly in the PAC controller.