This Seagate ST3000VX000 internal hard disk drive is a high-quality option for entry-level surveillance DVRs. With a storage capacity of 3TB and a rotation speed of 7200RPM, it provides reliable and fast performance for storing and accessing large amounts of data. The drive is designed with a 3.5in form factor and a Serial ATA-600 interface, making it compatible with a wide range of devices. Additionally, it features a cache size of 64MB, which can help improve the overall performance of the system.