TELEPHONE No. 331

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.  The pictures shows a standard Telephone No. 333, with no button.

Diagram for telephone circuit - N431.

Diagram for Button labels - N620.

History, Technical and General Information on 300 type telephones

Development of the Bakelite Wall Telephone

Collectors information

Keys for use in 300 type Wall and Table Telephones

How to restore Bakelite

Comparison chart of GPO 300 type telephones