Surface or panel weatherproof housing, solid state plug-in circuit board construction, remote alarm, primary range 0 to 18 megohm0cm, secondary range 0 to 1.8 megohm-cm and third range 0 to 0.18 megohm-cm, size 10.750 in. Lg by 6 in. H by 3.875 in. Dp, power 105 to 125 volts ac, 5 watts