Each expansion unit has 11 slots for cards.
- In total it is possible to connect up to 3 expansion units to the mainframe of automatic telephone exchange PANASONIC KX-TDA600, TDE600.
- Connection of the first expansion unit is made by means of a card of Panasonic KX-TDA6110, the second and third unit with Panasonic KX-TDA6111.
- Together with 10 slots of the mainframe 43 slots turn out
- Intellectual system of routing of outgoing calls (ARS)