Vintage SPLIT Ruler Wood Hinged Brass Trade? Tool Folds Up to 6" L Antique GUC

This is a unique old measuring tool of some sort... seems it would have a pretty specific or trade that it is made for.... if you KNOW what trade / tool this is, would you please shoot me a message ? From a nonsmoking environment. Features: • hinged & bendable & split Size: Unisex 6" Condition: Pre-Owned Good