(Manganin Coil) Precision quality consisting of 12mm (approx. 1/2”) thick rectangular brass block, non inductive, double covered Eureka Constantan wire is wound on bakelite spool, enclosed in a teak wood box. Accuracy ±0.1%. Specifications are same as per Cat. No. 850 consisting of 12mm (approx. 1/2”) thick rectangular brass block, resistance coils are made from doubled silk covered Manganin wire. Accuracy ±0.05%. Range d) e) f) g) h) i) j) k) l) m) n) Bakelite Moulded Plug 1- 10W No.