Internal computer hard drives. 12 pieces sold as a lot. All working fine and formatted ready to install: Maxtor: 120GB (ATA); 100GB (ATA) Western Digital: 1TB (SATA); 640GB (SATA); 250GB (SATA) x2; 200GB (ATA) x2 Seagate: 80GB (ATA) Samsung 40GB (ATA) x2 Hitachi 1TB (SATA)