R&K K&R Classic Map Measurer Metal housing Rotating counter .Fast reset-to-zero Precise metal measuring wheel Metric Scales: 1:25,000; 1:50,000; 1:100,000; cm ruler Standard Scales: 1:24,000; 1:62,500; 1:250,000; inch ruler Dial Diameter: 1.4" ,Weight: 1.5 oz.