Western Digital WD Green WD40EZRX 4TB IntelliPower 64MB Cache SATA III 6.0Gb/s 3.5" Hard Drive w/ (Certified Refurbished)- 1 Year Warranty WD Green hard drives reduce power consumption by up to 40% and offer best-in-class acoustics and operating temperature and 3rd generation SATA interface. IntelliPower - A fine-tuned balance of spin speed, transfer rate and caching algorithms designed to deliver both significant power savings and solid performance. Factory Recertified Hard Drive, Sealed in Factory Bag, Zero Bad Sector, Zero Power on Hours! 4 TB capacity holds up to 800,000 digital photos, 1,000,000 MP3 files, and 300 hours of HD video. Worry Free Return! 100% Full Refund