An American Indian Hand Wrestling Machine. Wow! It doesn't say which tribes it's endorsed by, but I'm sure they wouldn't lie. It comes with adjustable tensioners, a padded armrest, and it clamps to a table.
The other thing it does, & they don't tell you this, is that it somehow places your left hand on your right arm, as shown in the drawing.
So the next time you want to hand wrestle an Indian, plunk down your $7.98 and practice, son, practice. And since no partner is needed, you can practice at any time. (wink wink, nudge nudge)