Small, lightweight, and portable Professional multi-function high precision on-board compass Ideal for marine, vehicle, boating, traveling, hiking, outdoor activities, and more Outer tick of outer ring functions as a CM ruler; pointer rotates one full week equals one centimeter Inner tick of outer ring features a 1:50,000 scale, suitable for 1:50,000 maps Outer tick of inner ring features a 1:20,000 scale, suitable for 1:20,000 maps Inner tick of inner ring features a 1:5,000 scale, suitable for 1:5,000 maps Instructions: Align the pointer to zero at the 1:1 scale. Position the small wheel at the starting point on the map. Roll the device along the route to the destination. Based on the map scale, read the distance in kilometers. Material: Plastic Color: Yellow and White Package Contents: 1 x Map Rangefinder Note: The package includes only the items listed above; other products are not included. Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3 cm due to manual measurement.