Douglas Protractor Metric
|Douglas combined protractor and Parallel rule. Size 125mm with 1cm grid, in protective slip-case. Matt surface on one side for pencil calculations. Dual protractor angles and square grid. Metric serves as Romer for Australian topographic maps.Lay off a course or bearing; Rule parallel lines; Calculate magnetic and true bearings; Fix position by angles; Plot lines of position; Vector calculations; and more.