The GXP2020EXT delivers additional functionality, versatility and flexibility to Grandstream’s GXP2020 and GXP2010 enterprise IP phone series. The GXP2020EXT module features 56 programmable buttons (each with dual color LED) and up to 112 programmable buttons when two extension modules are daisy chained together. The GXP2020EXT module is connected to and controlled by the GXP2020 or GXP2010 with a short connector cable, providing the benefits of the additional keys instantly. Power and signaling are provided by the host phone. The GXP2020EXT supports the traditional call features on each of its programmable buttons, including BLF (busy lamp field), conference/call transfer/forward/pick up.