This is a Seagate Barracuda 1TB 3.5" 7,200rpm SATA hard drive which is compatible with the late 2009 and mid 2010 iMac ranges.

Because of the need for the internal firmware to match between the logic board and the hard drive on these ranges of iMac, standard drives cannot be fitted without altering the fan speed. These iMac hard drives need the corresponding manufacture thermal sensor cable.

If you did not have a Seagate drive fitted previously you will need to purchase the Seagate thermal sensor cable for your corresponding iMac range. (Every drive manufacture has a different connection.)