Decade Bridge 43379

This is a 4-decade Wheatstone bridge with ranges from 10 ohm to 10 megohm full-scale.

The unit has been modified at some time to take four "C" cells instead of the original 4.5 V 126 battery.

Intriguingly, it suggests that a 225 V battery is required for the 10 megohm range. The detector isn't particularly sensitive and instruments like this were often used with an external detector of better sensitivity.