Seagate Momentus Thin 320 GB 7200 RPM SATA 3Gb/s 16 MB Cache 2.5-Inch Internal Notebook Hard Drive (ST320LT007) 7mm z-height form factor enables thin chassis design for all segments of laptop computing. Seagate Smart Align technology provides a transition to 4K sectors without the need for software utilities. Features 16 MB Cache and 7200 rpm on a 2.5-Inch form factor