Magnificent 3inch (76mm) Brass Brunton Compass as a replica keepsake.
This is a replica of the Geologists Compass used by the USGS for land survey which has all sorts of strange abilities like taking bearings back to the user rather than from the user to a distant feature and so the dials North, South, West and East are reversed to read South, North, East and West.
It also has the USD500's original's Inclinometer for measuring the degrees of a slope and all features of the original operate but without the accuracy of the original so is a keepsake for a desk not a tool for a geologist or a hiker.