The 3TB SkyHawk Surveillance SATA III 3.5" Internal Hard Drive from Seagate is designed to withstand the stresses placed on it in a 24/7 surveillance system with 1 to 8 drive bays. With support for up to 64 high-definition surveillance cameras, this 3TB hard drive can hold a large amount of data and gives you the ability to upgrade and expand your security system. A SATA III 6 Gb/s interface, sustained data transfer speeds of up to 180 MB/s, and a 256MB cache all help to ensure uninterrupted data transfers. Furthermore, the drive's 600,000 load/unload cycles, 1 million hours MTBF and workload rating of 180TB per year, and <1 in 10 14 non-recoverable read errors also help to ensure a long operational life.