Seagate Momentus 320 GB 2.5-Inch SATA 7200RPM 16MB Cache Internal NB Hard Drive Bare Drive (ST9320423AS) 7,200 RPM Spin Speed, 16 MB Cache Buffer, SATA 3Gb/s interface with Native Command Queuing, 320 GB Capacity Optional G-Force Protection feature adds another layer of robustness for road warriors. QuietStep technology enables ultra-quiet load/unload acoustics Support for S.M.A.R.T. drive monitoring and reporting Ships in Certified Frustration-Free Packaging. Two Year Warranty 7,200 RPM Spin Speed, 16 MB Cache Buffer, SATA 3Gb/s interface with Native Command Queuing, 320 GB Capacity, Support for S.M.A.R.T. drive monitoring and reporting Optional G-Force Protection feature adds another layer of robustness for road warriors. QuietStep technology enables ultra-quiet load/unload acoustics Connector Type: 7 pin Serial ATA, Features: Native Command Queuing (NCQ), Perpendicular Magnetic Recording (PMR), QuietStep, Ramp Load Ships in Certified Frustration-Free Packaging, Two Year Warranty