The firmware version of the EVO CD will always be the same as the firmware version of your connected EVO 75/150. As long as your EVO CD is connected to your EVO 75/150, the firmware of the EVO CD will automatically update in sync with the firmware of the EVO 75/150.
You can check/update the firmware version of your EVO 75/150 by following the ‘Firmware’ steps in the manual here.