ST9250320AS - Seagate Momentus 250GB 5400RPM SATA 3GB/s 8MB Cache 2.5-inch Low Profile (1.0inch) H

G-Force ProtectionWhen a laptop is dropped, the most catastrophic damage to the hard drive occurs when the head scrapes across the surface of the disk, causing potential data loss. G-Force Protection, an optional drop sensor, protects the Momentus 5400.5 drive against shock by sensing when the system is in a free-fall state, moving the heads off the platter and locking them in place?all within three-tenths of a second.