Before you can fully understand a "Global Needle", you must understand a few basic principles of a compass. In order to get an accurate reading from a compass, the compass needle needs to be "balanced" in the capsule, so it does not drag on the top or bottom of the capsule. But, because the horizontal and vertical components of the earth's magnetic field vary considerably in different locations, a compass needle that "balances" perfect in North America will drag or stick in South America. As a result of these magnetic variances, the compass industry has divided the earth into 5 "zones", as identified in the map below. All of the standard compasses sold at The Compass Store are balanced for zone 1 (since most of our sales are in North America).
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But, what if you're not a world traveler? Why would you want a global needle? Well, the global needle's unique ability to handle tilts up to 20 degrees makes it perfect for hikers that don't want to break their stride. Not having to level the compass exactly makes it easier to take an accurate reading while you're still moving along the trail.
Full text - What is a Global Needle?
