Satin chrome blades and protractor headsDirect reading 0-180° in opposite directions, permitting the direct reading of angles and supplementary anglesReversible lock bolt allows choice of which graduated side of the blade faces the operatorProtractor heads are made of stable cast iron and finished with a smooth black finish or wrinkle finishTempered steel blades with accurate, machine-divided graduationsReversibleShoulder on both sides of blade allows tool to be reversed so same angle can be scribed or measured left and rightSpirit level indicates when the base reference surface is level.