HP 5851-4285 Scanner Memory PC Board Assembly is a scanner memory board assembly listed for selected HP LaserJet Enterprise multifunction printers. It is a service part for the scanner memory section of the device.
The exact part number is 5851-4285. The assembly is listed for the HP LaserJet Enterprise 700 Color MFP M775DN (CC522A) and HP LaserJet Enterprise MFP M725DN (CF066A), making those model references useful when identifying the intended printer family.