DECT 6.0 cordless accessory handset is for use with DS6421-3. Communicate instantly with any or all of the handsets within the system using Push-to-Talk Intercom. Handsfree conversations at the touch of a button with the handset speakerphone. Lines: 1; Telephone Type: Cordless; Caller ID / Type: Handset; Maximum Wireless Range: 800 ft.