An accurate, versatile and compact instrument for professional use by foresters, logging engineers and timber cruisers. Has a flat base and a straight edge (beveled and graduated to ¼”). Sold with interchangeable scales on sights that enable slope measurements to ± 30% or ± 60%. Features a vernier so the declination can be set off to within 5 minutes of arc. Compass comes with a ball joint socket, slope measurement scales, and case.