This product is either discontinued or we cannot get that from suppliers.
WD WD121PURZ 12TB Purple 3.5" SATA3 Surveillance Hard Drive, 256MB Cache, 7200 RPM, 245MB/s sustained transfer rate, Low Power Consumption.
Western Digital 12 TB, 256 MB, 7200 RPM 3.5" WD Purple Surveillance Hard Drive (WD121PURZ) WD Purple drives have been engineered specifically for the extreme demands of high temperature, 24/7 surveillance systems.