Liquid-damped magnetic steel needle and long-lasting precision pivot. Built-in magnetic declination screw and magnifying lens. Sighting mirror with luminous points. Clear protractor base is imprinted in red and features skid-proof rubber map feet. Clinometer measures heights and slopes to ±90°. Lanyard and declination tool included. Baseplate Dimension: 2-1/2" x 3-13/16".