- Grandstream expansion module - Delivers additional functionality, versatility and flexibility to Grandstream"s GXP2020 and GXP2010 enterprise IP phone series - Ideal solution for offices that manage high call volumes or an office receptionist - 56 programmable buttons (each with dual color LED) and up to 112 programmable buttons when two extension modules are daisy chained together - Supports for traditional call features on each of its programmable buttons, including BLF (busy lamp field), conference/call transfer/forward/pick up - 56 programmable buttons per module - Busy Lamp Field (BLF) - Speed dial for each line - Daisy-chain 2 modules for 112 programmable buttons - Conference/call transfer/forward/pickup GSGXP2020EXT