Ativa 5.8 GHz Expandable Cordless Answering System with speakerphone in Handset and Base 5.8 GHz, Battery Backup for Power Failure Operation Last 10 number redial, Vibrating Ringer, Digital answering system Polyphonic Musical Ring Tones, 50 name/number directory in handset Spare Battery Charger, Call Transfer, Conferencing Personalized Ringing Option, Number announce Caller ID