An engineer had one made for me that looked just like that for a project we were doing. Mine was a 45 pound torque limiter. If I remember correctly it only snaped at 45 pounds and would over torque if you continued, or something like that. Clamp up an extension, whip out your wrachet or torque wrench, and try to determine if that is what you have. With a little effort, you can determine the value with your torque wrench, if that is indeed what it is.
Cheers, Dave