Suunto A-10 CM Recreational Compass

• Balanced for northern and/or southern hemisphere Fixed declination correction scale Jewel bearing Detachable snap-lock in lanyard. Easy to detach for working with the Size: 57 x 90 mm Weight: 27 g / 0.95 oz.

Manufacturer's Description -------------------------- User Friendly Recreational Compasses The A-range of recreational compasses is a series of handy, well designed, navigational aids which are assets in any environment. All four models in the series (A-10, A-20, A-30 and A-40) are compact, high-accuracy instruments made from durable, clear, scratch resistant acrylic that have been ergonomically designed to fit into the palm of your hand for optimum ease of use. These light-weight compasses feature a fixed declination correction scale as well as a patent-pending lanyard snap-lock enabling the compass to be easily detached from the lanyard. 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. Previously, the globe was divided into five different balance zones in which specific compasses functioned. However, as people travel more and more, the need for a compass with a greater geographical range has increased. Thanks to Suunto's 'Two Zone System' there are only two balance zones to consider in compass use - the northern hemisphere and the southern hemisphere. In practice, this means that a Suunto compass designed for the northern hemisphere will still work for a fair distance into the southern hemisphere, and vice-versa.