Silva 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.