Seagate 3TB 64MB Cache 7200RPM SATA III 6.0Gb/s (Heavy-Duty) 3.5-inch Internal Hard Drive -NAS, RAID, PC, CCTV DVR Seagate 3TB 64MB Cache 7200RPM SATA3 , 6.0GB/s Heavy Duty, Enterprise NAS Raid,CCTV and PC