ID: 
45
Maker's Name: 
Cambridge Instrument Company
Where made: 
England
Dimensions: 
12 × 10 × 8 cm

Enables current passed to galvanometer to be reduced by known factor variance ratios of attenuation from 3 to 10,000 according to switch pos. Constant resistance 100,000 ohms presented to current source.Manganin wire resistance coils used.