Adopt plastic material, this ruler is and lightweight, making it easily to carry and use. Half moon shaped, with an outer edges of 0-6400miles and 0-360degrees. Bottom line reads 1:25000meters and 3.3kilometers respectively. The second line reads 3 kilometers at the verification meter and 1:63360meters respectively. An essential tool for precise measurements in various field, such as engineering, architecture, and DIY projects., Manufacturer: Hyclam