Panasonic KXTGA400B 2.4GHz Accessory Handset for KXTG4000B Expandable Phone (Black) (KX-TGA400B) Additional handset for Panasonic KXTG4000B 4-line phone system 2.4 GHz digital spread spectrum operation Caller ID with call waiting capability, 30-call history; 50-number directory Supports 3-way conference calling, 2-way paging/intercom Up to 8 hours talk time