P.O. BOX – 3 Ratio, Plug Type

(Constantan/Manganin Coil) The 3-Ratio P.O. Box has sixteen non-inductively would coils 1, 2,2, 5, 10, 20, 20, 50, 100, 200, 200, 500, 1000, 2000, 2000, 5000 ohms and two proportional Ratio arms each with coils of 10, 100, 1000 ohms. Heavy, superior quality double brass terminals are provided and panel is clearly engraved with the nominal resistance values. Two spring keys having good contact for battery and galvanometer is also provided.