Western Digital Caviar SE (WD3200AAKS) 320GB 16MB Cache 7200RPM SATA 3.0Gb/s 3.5" Internal Desktop Hard Drive [Certified Refurbished]- w/ 1 Year Warranty 320GB Capcity, 7200RPM, 16MB Buffer Size 3.5-inch, SATA II 3.0 Gbps Desktop Hard Drive Best for Desktop PC/Mac or all-in-one PCs, Surveillance CCTV DVR Passed Factory Diagnostic Software + RE-CERTIFIED by State-of-the-Art software - Full "Sector-by-Sector" test to ensure best HDD quality! ZERO Bad Sectors! "Like New Refurbished" Worry Free Return! 100% Full Refund