The Compact Tracker Survival Button Compass is an oil filled, pressurized, military quality compass. The small size of the Compact Tracker Survival Button Compass, 20 mm, makes it a perfect fit for any pocket, survival kit or pack. The Compact Tracker Emergency Button Compass and very similar compasses are featured in many of our high quality survival kits as well as survival kits worldwide. The Compact Tracker Button Compass features: a compact diameter (20mm), is oil filled for needle dampening, pressurized, and is water resistant to 30 meters. One should bear in mind that the button compass is only a guide, not to be used for detailed orienteering. The origin of the button compass is in escape and evasion and was often used by downed pilots over unfamiliar territory. It was made small and durable in an effort to make it easily concealable. These compact survival compasses were and are used as an aid for locating a general direction, rather than a precise map reading instrument. Button compasses are not often used in orienteering, competitions, or as a primary source of accurate direction. For general direction finding, small size and durability, you simply cannot beat the Best Glide Compact Tracker Button Compass.