Brass Open Face Mariner's Pocket Compass with Beveled Glass Solid brass reproduction of an antique open face pocket compass with sturdy beveled glass Air-damped compass with a large, freely rotating compass card that settles quickly on North; Black print on bold yellow face for accurate readings Card is marked with cardinal & ordinal directions as well as the 360-degree system widely used by civilian navigators today North at 0 = 360, South at 180, East at 90, and West at 270 The Mariner's compass substitutes the West point with an O, an abbreviation for the Latin term Occidens, to fall or set, as in the sun The compass is 2 5/16 inches in diameter, 7/16 inch thick, and weighs 2.3 ounces