HP 4TB 3.5-inch SATA 6Gb/s 7.2K RPMMidline (MDL) Non-Hot-Plug (NHP) Hard Drive HP serial number and firmware HP Certified Hard DrivePart Number(s)Option Part# 801888-B21SmartBuy Part# 801888-S21Spare Part# 801925-001Assembly Part# 693671-003Model# MB4000GCVBU