NEC DSX 34Btn Full Duplex Super Display Telephone Black can be used only with NEC DSX systems does not work independently. The DSX system s most sophisticated telephone instrument. Features a large 9 line-by-24 character backlit alphanumeric display with 12 Interactive Soft Keys for intuitive feature access. 10 Personal speed dial bin keys. 24 Programmable feature keys. 12 Fixed function keys. NEC DSX 34 Button Super Display Telephone Black has a built-in speakerphone. Backlit keypad. Headset jack. Dual LEDs. Ring/message lamp (to show ringing Caller ID and voice mail messages). Built-in wall mounting. Innovative two position angle adjustment. Color: Black.