- Accessory handset only�requires a CS6619 CS6629 CS6648 or CS6649 series phone to operate - DECT 6.0 digital technology - 50 name and number phonebook directory - Voicemail waiting indicator - Last 10 number redial - Mute - Any key Answer - Volume Control - RoHS Compliant - Hearing Aid Compatible - Intercom between handsets - Conference between an outside line and up to 2 cordless handsets - Trilingual prompts allow you to choose between English Spanish and French