Inhouse product
WD Purple Surveillance SATA HDD is built for 24/7 always-on surveillance in high-definition security system, 4 terabyte capacity, 3.5-inch form factor, 5400 RPM rotational speed, ATA-600 interface, 6 Gb/s transfer rate, 64MB cache, 5.8 x 4 x 1 inch dimension.