ATT ATT-CLP99007 ACCESSORY HANDSETS WITH CIDCompatible with AT&T CLP99487 and CLP99587 expandable cordless phone systems (sold separately) DECT 6.0 technology offers crystalclear callsLCD screen provides ataglance informationCompatible with caller ID and call waiting featuresCaller ID announce speaks the name of incoming callers, so you'll know who's on the line when you pick upCall waiting/caller ID service required from your local telephone companyConnecttocell function lets you pair the handset with your mobile phone, so you won't have to worry about dropped calls or weak cellular signalsCompatible with Siri, S Voice and Googleâ„¢ Now for flexible useIntercom between the handset and base allows simple communication between offices and rooms200number phonebook provides easy access to your contacts list