Sharp AM-300 Online Manual page 26

Extension phone (AM-400 only/optional)
If desired, you can connect an extension phone to the TEL. SET socket on the
machine.
Germany:
The TEL. SET socket is not available on the machine. We recommend that
you plug a telephone (for example a cordless phone) into the middle
connector of the TAE wall outlet and the fax line cord into the left connector.
Switzerland, Austria:
An extension phone cannot be used.
1
Remove the seal covering the TEL. SET socket.
2
Connect the extension phone line to the TEL. SET socket.
Installation
19