2 3/4 inches in diameter. Determines both the magnetic heading of an object, as well as its angle of elevation or declination. Angle of the pendulous arm can be read while simultaneously viewing the object. A needle lift mechanism protects the compass jewel during transport. Custom engrave-able on the front and/or back of the compass. The compass can determine both the magnetic heading of an object, as well as its angle of elevation or declination. An azimuth heading can be determined using the front button sight, the sighting hole, and the scribed line in the mirror. When the compass is placed on its side and the mirror is placed in the 45 degree position, the angle of the pendulous arm can be read while simultaneously viewing the object. The compass has a needle lift mechanism to protect the compass jewel when transporting. Moving the needle lift lever activates the needle lift mechanism to lock the needle. Note: all custom engraved orders are final sale and cannot be returned or exchanged. This item is made of brass.