I have one, though its legs are longer - 4" outside. It's for drawing accurate cut lines on rectangular things like table legs. It could also be used as an angle transfer gauge, but the most acute angle it will fold to is about 85 degrees. Mine is marked SS-4.
They both show up on the current website in the Legendary Tools section. Mine is an SS-4; yours is an SS-2. The SS stands for Saddle Square.
Squinting closely at your picture, yours is indeed marked SS-2, not 35 or 33