This listing is for a set of two Maxtor DiamondMax 23/21 500GB SATA III 3.5" internal desktop hard drives. These drives are compatible with PC/MAC/Linux and have a rotation speed of 7200 RPM. They have a storage capacity of 500GB and a cache of 16MB. The Maxtor DiamondMax 23/21 is a reliable and high-performing hard drive model that supports HDD drive types and has a transfer rate of 6Gb/s. It is a product of the DiamondMax product line and has been manufactured in Thailand. This unit type is suitable for those who require high-capacity storage for their desktop computers.