Panasonic Digital Phone for NS 4.3" COLOR LCD 12X4 Self-Labelling keys DT PHONE BLACK KX-DT680-B4. 3" COLOR LCD 12X4 Self Labelling keys KX DT680 B Next generation digital proprietary telephone, with a 4. 3" color back lit display, 12 x 4 pages of programmable keys, and full duplex speakerphone with an upright & sleek design. KEY FEATURES 4. 3" Color LCD with backlighting 12 x 4 freely programmable function keys EHS (Electronic Hook Switch) Speaker Phone, handset and headset with full duplex Available in black color