The HP AP858A is a 300 GB internal hard drive that has a large form factor of 3.5 inches. This dual port HP 300 GB hard drive has a spindle speed of 15000 RPM, and it is compatible with the HP StorageWorks P2000 G3 MSA array system. The HP AP858A has a data transfer rate of 4.7 Gbps. It is considered an enterprise level hard drive. This internal hard drive is hot swappable. This means that this HP 300 GB hard drive can be added to or removed from a PC or other electronic device without having to reboot the PC. This factor saves time for those systems that must be running all the time. Connectivity for this HP 300 GB hard drive is available via a 6 Gbps SAS or serial attached SCSI connection. This hard drive has a height of 5.1 inches, a width of 8.4 inches, and a depth of 12.5 inches. It weighs 2.4 lbs.