You can transmit dual-tone multifrequency (DTMF) signals to control devices such as an answering machine or automatic information system. 

Press the key. The LED lights up. 

Select and confirm. 

Enter the code. 

You can use the keys "0" through "9", "*", and "#" to transmit DTMF signals. 

Ending the call also deactivates DTMF suffix dialing. Your system may be configured so that you can start DTMF suffix-dialing immediately after setting up a connection.