The Tandem is a rugged, compact instrument that will allow you to take both slope/height measurements and compass bearings. Its aluminum housing is corrosion and water resistant. The clinometer scale is in percent and degree (0-90 deg., 0-150%) while the compass scale is 0-360 deg. The clinometer and compass are graduated in 1/2 deg./1% increments and each is individually calibrated for an accuracy of +/- 0.25 deg. Also includes an inch scale on the side, cotangent and cosine tables on the back, 1/4″-20 threaded mount for camera tripod, carrying case and neck lanyard. Sold with or without declination adjustment.