and high quality Small, and portable. Professional Multifunction High Precision Onboard Compass. Great for marine, vehicle, boating, traveling, hiking, outdoors, etc. The outer tick of outer ring is CM ruler. The pointer rotating a week is a cm. The inner tick of outer ring is 1: 50,000 scale, applying to the 1:50,000 map. The outer tick of inner ring is 1: 20,000 scale, applying to the 1:20,000 map. The inner tick of inner ring is 1:5,000 scale, applying to the 1:5,000 map. Instruction: Move the pointer to zero, . at the scale of 1:1. Align the small wheel to the measuring address, slip(rolling) to the destination along the route. According to the map scale, read the number of kilomet Material:plastic colour:Yellow+ White Package Contents: 1 x Map Rangefinder Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is + 13cm.