For use with deflection magnetometer or tangent galvanometer Comprising  of a plastic  moulded case of 125mm diameter, with  black aluminium dial graduated in degrees 0-90 four times, anti-parallax mirror slot. Permanent magnet (small in size) is used. The short magnetic needle has a synthetic sapphire bearing and a light aluminium pointer designed for precise readings and maximum damping. The compass box has a hollow circular cavity at bottom to fit tangent galvanometer stand or deflection magnetometer base.