HP 640GB 5400RPM SATA 3GB/s 2.5-inch hard drive (part number 669300-001) designed for external storage applications and legacy system expansion. This 2.5-inch form factor drive operates at 5400 RPM with SATA 3Gbps interface connectivity, delivering sustained throughput suitable for backup, archival, and secondary storage workloads. Compatible with HP external enclosures, docking stations, and standard SATA-compatible systems requiring additional capacity. Typical use cases include portable backup solutions, external storage expansion for laptops and desktops, and non-performance-critical data repositories. This drive has been tested and guaranteed fully functional; contact G5 Network Group for availability and pricing via quote.