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.