Double-side ruler: the ruler's one side is metric scale (30 cm), another side is inch scale (12 inches), both inches and centimeters for easy conversion Wooden measuring ruler: our ruler is made of good quality wood material, very tough and not easy to bend, with smooth surface, easy to use Accurate scales: the scale of the ruler is very clear and accurate, will be helpful you in measuring your items accurately and architectural drawing Applicable to: wooden rulers fit for office, home using, especially for teachers using in math, science class or other occasions Quantity: the package includes 25 pieces of wood rulers, enough quantity can satisfy your use of various occasions; Note: do not contact with water, Manufacturer: SZLFSX