Toshiba DKT-2020SD Business Telephone System (20-Button LCD Speakerphone) Programmable 20 LED Buttons Eight Fixed Keys Provide: Speaker On/Off, Message Waiting, Last Number Redial, Conference, Transfer, Hold, Volume Control. Compatable with Toshiba Dk14, DK16, DK40, DK40i, DK280, DK424, DK424i, CTX100 and CTX670 systems Speaker & LCD Telephone Display