The Silva Explorer base plate compass 203 was designed for those who want to get off the beaten path. Contoured base plate comfortably fits the hand. The extended base plate has an inch ruler and 1/10 mile scales for USGS 1:24,000 and 1:62,500 maps - ensuring accurate mapping and plotting. Features; 2° dial graduations, Built-in magnifier for map details, Declination scale, 1/10 mile scales for USGS 1:24,000 and 1:62,500 maps, Inch ruler, Lanyard. 2 x 4 inches, 1.0 oz. pack weight.