WD Purple 4TB 3TB 2T Surveillance HDD 64M Cache SATAIII 6.0Gb/s 3.5" Western Digital Internal Hard Drive 1T 500G 6TB HD Harddisk. WD PURPLE SURVEILLANCE HDD. The WD Purple drive is designed for both DVR and NVR security systems, and is compatible with many of the the leading surveillance and security manufacturers.
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