This compass can determine both the magnetic heading of an object, as well as its angle of elevation or declination. A pendulous arm beneath the compass needle can read the angle in degrees of elevation or declination. The interior of the compass lid has a mirror with a round sighting window. A front sight folds up, and the window in the lid has a scribed line to serve as a rear sight. The compass rose is marked in degrees and has the original old markings. The inclination scale is printed mirror imaged so that when taking a elevation or declination measurement, the lid can be placed in the 45 degree position, and the angle can be read while simultaneously viewing the object. The compass has a needle lift mechanism to protect the compass when being transported. The compass measures 3" in diameter, 1 3/8" thick, and weighs 14 1/4 ounces. A leather case comes with this item. The case has a rear belt loop and the front of the case is embossed "Stanley London."