Harris CS80C286 -20
As mentioned in the story of this 8MHz 286 some companies made 286's running at 20 or 25MHz. Harris was one of those manufacturers to get these 286-beasts on the planet.
I bought the 20MHz 286 long time ago and haven't seen another 20 or 25MHz 286 ever since! Imagine it's difficult to get one these days.

