Seagate 500GB Laptop HDD SATA 3Gb/s 8MB Cache 2.5-Inch Internal Drive Retail Kit (ST905003N1A1AS-RK) 500GB storage capacity Up to SATA III, 6Gb/s interface QuietStep technology enables ultra-quiet load/unload acoustics Best-Fit Applications; Mainstream laptops, External storage solutions/boxes Perpendicular recording technology increases performance and reliability Seagate Smart Align technology provides a transition to 4K sectors without the need for software utilities