Yes. NVR can retrieve and display the recoded audio/video data in HDD carried from another NVR.

However, NVR classifies another NVR’s HDD to ‘other HDD’ type and does not support data recording until the HDD is formatted. That is, if you want to record data to the HDD carried from another NVR, you should back up data in HDD to alternative storage device if needed, then format the HDD.