On Monday, April 28, 2014 3:12:29 PM UTC-4, wrote:
a 2 inch ball is within 2 mm of spec....

The problem is which side of the spec it is on. It's really easy to get
the hitch stuck on the ball trying this. A 1-7/8" ball doesn't get stuck
and otherwise works OK (it's about 2.5mm too small). I've used one to
tow my trailer successfully. (The trailer came with a 50mm ball, but the
shank was 1" and my SUV had a Class II receiver so it could only take 3/4"
shank balls.)

This looks like a really great deal.

Matt