6EU83AT 512GB is an SSD type hard drive which can fit 512 GB of data. The form factor is M.2, which allows the hard drive to connect directly to the motherboard.
From Clove Technology
HP Z Turbo Drive M.2 512 GB PCI Express 3.0 TLC
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HP Z Turbo Drive M.2 512 GB PCI Express 3.0 TLC