This product is either discontinued or we cannot get that from suppliers.
Western Digital WD101KFBX, Red Pro, SATA 6.0Gb/s, Capacity 10 TB, 7200 RPM, 256MB, FF 3.5".
Designed specifically with medium or large scale business customers in mind, WD Red Pro drives are available for up to 24-bay NAS systems. Engineered to handle high-intensity workloads1 in 24x7 environments.