4
Headpieces
The following headpieces can be used with these telephones:
— Mirage
®
 — Receiver fits over either ear. Not for noisy environments.
— StarSet
®
 — Eartip fits in ear canal.
— Supra
®
 Monaural — Adjustable headband and soft ear cushion.
— Supra Monaural Noise-Canceling (NC) — Same as above with 
noise-canceling microphone that reduces background noise transmission 
by up to 75 percent.
— Supra Binaural — Sound in both ears.
— Supra Binaural Noise-Canceling (NC) — Same as above with 
noise-canceling microphone on flexible boom; features windscreen and 
reduces background noise transmission by up to 75 percent.
Note:  The privacy of the Whisper Page announcement cannot be 
guaranteed when telephones have headset adapters other than the 
M10L-8400 plugged into the Handset jack. The M10L-8400 
(Comcode: 407639715; PEC: 3122-022) is the only headset adapter 
that should be used for the 6400 Series terminals.For more 
information, see the Whisper Page instructions in the Voice Features 
section.
Call-Handling Features
Conference
The Conference feature allows you to conference up to six parties 
(including yourself) on a call.
To add another party to a call (for a total of six parties)
1. Press .
Present call is put on hold.
2. Dial the number of the new party and wait for an answer.
3. When you want to add the new person, press   again.
All parties are now connected.
4. Repeat Steps 1 through 3 for additional conference connections.
To add a call you have put on hold to another call you are
connected to
1. Press .
Red light next to   blinks.
2. Press and then release the switchhook.
3. Press   again.
All parties are now connected.
Conf
Conf
Conf
Hold
Conf