Previously had this listed as a boom vang but I was corrected and it's really a custom block and tackle system made by Garhauer.
We bought it at the last boat show in Annapolis - where I am located - and only used it once.
It was purchased to help us lift a heavy outboard engine from the end of our mizzen boom to the rail.
It has a triple block and a triple block with a jam cleat.
Selling for $150 including shipping.
Sorry if I mislead anyone. I was not sure what to call it.