Post Office Box, Plug Type

Plug Type, In Polished Wooden Box With Hinged Lid And Panel Printed With Circuit Connections. Resistance Coils Are Double Silk Covered And Wound Noninductively And Have A Negligible Temperature Co-Efficient. Three Pairs Of Ratio Arms Of 10, 100, 1000O And Resistance Arms Contains 16 Coils From 1 To 5000O With Infinity Plug. Total Value 11110O. Provided With Two Spring Keys Having Special Contact For Battery And Galvanometer Fitted. Accuracy Of Coils 100O To 500O Is ± 0.05% And Other Coils In ±0.1% Of The Marked Value. (Coils Of Constantan Wire)