AT&T® ML17929 Two-Line Speaker Phone with Caller ID/Call Waiting, BlackThis ML17929 corded telephone features 2 line operation for incoming and outgoing calls on two separate lines with one unit, giving you the flexibility to manage professional and personal business at once. Navigation buttons with rapid scroll, 100 name number directory. Visual message waiting indicator, 18 one & 2 touch memory, Switchable data port & headset compatible. Black 2 Line With hold, mute, caller ID call waiting capability on both lines