HP-ST9500530NS Seagate Constellation 500GB 7.2K RPM 32MB Buffer 2.5 Inches Form Factor SATA300 Hard Drive. New Bulk 2 Years warranty.

Specification
Form Factor 2.5 Inches 
Capacity 500 GB
Interface Type Serial ATA-300
Buffer Size 32 MB

Performance
Drive Transfer Rate 300 MBps external
Internal Data Rate 95 MBps
Seek Time 8.5 ms average 
Track-to-Track Seek Time 0.8 ms
Average Latency 4.16 ms
Spindle Speed 7200 rpm
 
Expansion / Connectivity
Interfaces 1 x Serial ATA-300 - 7 pin Serial ATA
Compatible Bays 1 x internal - 2.5 Inches