DK3-21c Standard Elegant design, European style which will satisfy all demands of the business office. The DK3-21c is simple in design but offering complete features and functions that are required in today’s business environment. TheDK3-21c Digital Key phone equips with maximum 10 programmable (CO, Extension, Functions and Speed Dial) keys with dual-color LEDs and 17 functional keys. The DK3-21c series Digital Key phone can used at all Gx Series telephone systems and Hybrid IP Communication systems on a DK port interface. As with all other DK series handsets the DK2-21c utilises single pair wiring making deployment over existing installed cabling simple and painless.