Accurate and Reliable Mirror Compasses The MC range of mirror compasses provides an invaluable tool for those who place a particular premium on accurate and reliable directional measurements; for example surveyors, miners, architects, rescue patrols, hikers, boaters and the military. The declination adjustment system, standard throughout the range, is especially useful when working in areas of large magnetic variation, while the sighting notch provides superior accuracy. The MC-2 model is also available with the Global Balancing System. Field compasses in general Mechanical compasses have been working as the navigator since several thousands of years. Still today magnetic compass is environmentally friendly, cheap and the most reliable tool when choosing the course. The oldest Suunto field compasses, which are still in use, are manufactured in 1938. A high quality field compass hardly needs any other service than washing in fresh water from time to time. The compass works without any external power supply. The compass gets its power from nature - from the magnetic north pole. COMPASS BALANCING Two Geographical Balancing Zones The vertical intensity and direction of the earth's magnetic field, the inclination, influences the horizontal plane of a compass needle according to the latitude where it is used. Due to inclination, compasses must be balanced for different geographical zones in order to keep the needle in a horizontal position.