I know its a Pratt Whitney Aircraft special.  But what is it for, and how is it used. Drive 1/2, opening 9/16  length about 7 inches.

PWA-2399 Wrench, Socket (6.5"L) 1/2 Male drive, 9/16 Cyl Base Nut, R1830,R2000

Radial engine cylinder head to block nuts.

An obstruction wrench, angled to clear the cooling fins on the side of the cylinder.

Nearly all of then are male drive, and I still have no idea why...


Reminds me, I need to repost the PWA tools list, I lost a few edits from the old site, but have most of it...