It's for a truth dyad crank arm system this is the part you screw on to the window 1 inch 1/4 by 2 1/2 inch
Dave Sr. from SWISCO responded:
August 3, 2016
Hello! Please see our 39-514, I believe this could be what you're looking for. These actually come with a corrosion resistant finish, so you shouldn't have to worry about the replacement rusting up.