Yes. The HD-DVR has 64 GB of internal CompactFlash storage. It takes approximately 16 hours of 720p high definition video to fill the storage. Once that internal card fills up, the video is saved in a FIFO Method (First In, First Out).
The HD-DVR has 1 removable CompactFlash card, typically 32 GB in size. Additional CF cards can be swapped in order to move video files from the internal storage. When either card is near maximum capacity a pop-up message will display.