5SS0V26412 512GB is an SSD type hard drive which can fit 512 GB of data. The form factor is M.2 and it connects the hard drive directly to the motherboard.
From SmartTeck
Lenovo 512 Gb SSD M.2 2280 PCIe3x4 FRU00UP437, 512 GB, M.2 - Approx 1- -
Athema Services
lenovo 512 gb ssd m.2 2280 pcie3x4 5ss0v26412 - eet01
Compadvance
LENOVO 512 Gb Ssd M.2