Panasonic KXT7640E DSS Console - White60 Button Busy Lamp Field Handsfree on hook dialling Note: The Panasonic KXT7640 DSS requires 1 extension port. The Panasonic KXT7640 DSS is compatible with all Panasonic KXT7600 series phones. The KXT7600 series key telephones are compatible with the Panasonic KXTDA Telephone System. The Panasonic KXT7640E DSS Console is pictured with the Panasonic KXT7636E Telephone. The Panasonic KXT7636E telephone is not included.