This is a vintage Brown & Sharpe 496 bevel protractor with a 6" blade, made in the USA. It is a tool used for measuring angles in metalworking and machining applications. The brand Brown & Sharpe is known for producing high-quality precision measuring instruments. The protractor type is a bevel protractor, which is used for measuring and setting angles to a high degree of accuracy. This particular protractor is a collectible item for those interested in vintage metalworking tools.