WD TDSourcing Purple Surveillance Hard Drive WD40PURX - Hard drive - 4 TB - internal - 3.5" - SATA 6Gb/s - buffer: 64 MB - for WD My Cloud EX2, EX4
Western Digital Purple 4TB 3.5" Surveillance Hard Drive:4TB capacitySATA III interfaceHolds up to 2,666,000 photos, 1,142,000 songs or 2,100 hours of HD video and more