DK6-21 Elegant and stylish with two tone colors, the DK6 series Digital Key phone meets all needs for Gx series Hybrid IP Communication system. The DK6-21 phone would hold a place on the desk of any busy executive, or suit those who desire a top of the line telephone. The DK6-21 is equipped with 36 programmable keys (CO, Extension, Functions and Speed Dial) with dual-color LEDs and 8 functional keys. It also has optional Bluetooth interface that a Bluetooth headset could be connected with. As with all other DK series handsets the DK6-21 utilises single pair wiring making deployment over existing installed cabling simple and painless.