AT&T E5917 - 5.8 GHz Exxpandable Cordless Answering System with Dial-In-Base Speakerphone 5.8 GHz Digital Spread Spectrum Frequency Hopping Technology Expandable System (Use up to 8 handsets through a single phone jack) Handset Speakerphone 51 Name & Number Directory Clearspeak Duplex Speakerphone in Base