WD Purple WD20PURZ 2TB 3.5 Inch SATA III Surveillance Internal Hard Drive More Cameras. More Clarity. More Surveillance. Capture it in Purple - Engineered specifically for surveillance security systems. - Supports up to 180 TB/yr workload rate*. - Tuned for write-intensive, low bit-rate, high stream-count applications typical to most surveillance applications. - Prioritized write-operations for maximized surveillance performance. - TLER & ATA streaming support. - Support for more than eight bays**. - Tarnish-resistant components**. *Workload Rate is defined as the amount of user data transferred to or from the hard drive. Workload Rate is annualized (TB transferred ? (8760 / recorded power-on hours)). Workload Rate will vary depending on your hardware and software components and configurations. **For capacities 4TB and higher. Model WD Purple WD20PURZ Capacity 2TB Interface SATA III Cache 64MB Rotational Speed 5400RPM Data Transfer SATA III: 6.0 Gbit/s Physical Drive Size 3.5\" Packaging OEM anti-static bag