This is the Intel 8088. A beast with 29,000 transistors that could be clocked up 8MHz in its 1979 heyday, it was the second chip to use the x86 architecture, and the brains inside the original IBM PC.
Oh Craigslist…so many idiots. Case in point: some dude is trying to pass off an ancient IBM PC running Windows 3.11 as being “ideal for home or office” and “a great deal” at $US500.