The horizontal and vertical components of the earth's magnetic field vary considerably in different locations. For this reason Suunto compasses are balanced for 5 different zones. If the compass is used in an adjacent balancing zone, many compass pointers will tilt only slightly. However, the farther a compass is used from its correct zone, the more its pointer tilts. In extreme cases, the pointer will stick. For this reason, it is extremely important to know in which country a compass will be used.