Western Digital Red Pro 2TB 3.5-Inch SATA III 7200rpm 64MB Cache NAS Internal Hard Drive (WD2002FFSX) Available in large capacities with support for 1-16 bays 5 year limited warranty Enhanced reliability with 3D Active Balance Plus and error recovery controls with NASware 3.0 Extended drive testing to ensure each drive is tested for extended reliable operation Vibration & Shock protection