The Terra Expedition S is part of Silva's Terra range: a new series of sighting compasses made of recycled materials with 90% less carbon emissions. Cover and grip ring in REVO materiel with 90% less carbon emissions. Silva Terra Expedition S features easy-handling Dryflex housing, silicon rubber feet for precision map work, detachable safety-release lanyards, night-enabling luminous markings, magnifying lens, map-measuring scales in mm or inches, 1:25,000, 1:50,000 and GPS scales, plus built-in adjusters for magnetic declination (including permanent local adjustment). The Expedition S can also map-measure 1:40,000, has both a clinometer for measuring slope angle, and 45-degree angle assistance on the mirror-sighting function. The slope card is great both for detecting avalanche risk and for determining how challenging your journey will be. By knowing the slope you can also judge any extra distance that you need to go due to the slope. The scale lanyard has two scales on it; 1:25, and 1:50, which facilitates measuring the distance of your hike. Since it's soft and bendable it's easy to place it directly on to your route on the map. For tough terrain that demands for a mirror sighting compass Expedition S is your optimal companion.