Key telephone system adapted to respond to information stored in

Key telephone system and interface unit for key telephone

Key telephone system and maintenance method therefor

Key telephone system and maintenance method therefor

Key telephone system capable of regulating volume of handset

Key telephone system capable of simulation by button operations

Key telephone system having a plurality of telephone numbers...

Key telephone system provided with telephone sets connectable to

Key telephone system providing selection of key or PBX operation

Key telephone system reading dialing information from a portable

Key telephone system with circuitry for adding a third caller to

Key telephone system with cordless terminals

Key telephone system with distributed control

Key telephone system with means for operatively connecting anoth

Key telephone system with reduction of delay of ring tone genera

Key telephone system with virtual private lines

Key telephone system with virtual private lines

Key telephone system, key telephone, interface unit, and...

Key telephone unit and key telephone system