The Silva Expedition 4 Compass features:
The Silva Expedition 4 Compass is a unique compass that has both an optical precision sighting system and a SILVA 1-2-3 SYSTEM compass in the same unit, providing unbeatable precision and versatility in the field. Accurate bearings can be taken to within half a degree. The Silva Expedition 4 Compass also includes a luminous compound that can give light for up to 4 hours when activated by daylight or a flashlight.
Big base plate, makes bearings easy, an easy to read dial makes accracy simple. The only choice for tough navigation.