Hard Disk and Video Surveillance: recordings of video surveillance systems are made on special disks, even if technically similar to the disks of common computers, to obtain a guarantee of operation video surveillance systems are certified with audio-video disks, including the Purple series of Western digital. This series of Western Digital Hard Disks guarantees absolute reliability over time, being designed to cover all the typical problems of video surveillance recording systems, therefore H24 operation, higher temperatures, constant speed and much more, it is essential for your security systems to use only certified audio-video discs.