BELLSET 20

GPO bellset Nr20 is a simple switchboard with just a single extension. It was used by secretaries that either answered incoming calls themselves, or transferred the call to their boss. The line to the exchange can be held while she transfers the call. The set is housed in a beautiful mahogany box. It has two bells and a magneto generator. An ENGAGED sign  appears behind a window when the extension is connected to the exchange.