Features Probably the most resourceful compass in the world for artillery; target acquisition and command posts. The Expedition 54 is a unique compass featuring both an optical precision sighting system and a SILVA 1-2-3 SYSTEM compass in the same unit, giving unbeatable precision and versatility in the field. Bearings can be taken with accuracy to within half a degree. 6400 mils on the graduation ring and 6400 mils and 360 degrees on the sighting scale. With beta light i.e. will give continuous light up to 7,5 years.