Bevel Protractor with Double Square Head (Rare).  18” (450 mm) long.  The double head (flat on both sides of the head) is quite rare for a protractor style square.  English/metric with 32nds, 64ths on one side and mm, .5 mm on the other.  The head is 2-9/16” wide and 9.875” long.  Clearly engraved graduations.  Satin finish.  Very good used condition.  It rotates approximately 45 degrees in either direction.  It is exceptionally wide and heavy for a protractor square.