Bakelite wall telephone for use in CB & AUTO areas on PBX extensions, systems that require recall facilities and certain extension plans.

This telephone has provision for one button in the case moulding.

Circuit diagram N431.

Click here for the circuit diagram - Web users - CD users

History, Technical and General Information on 300 type telephones

Collectors information

Click here for Button labels  - Web users - CD users

Keys for use in 300 type Wall and Table Telephones

How to restore Bakelite

Comparison chart of GPO 300 type telephones

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Last revised: September 19, 2010