Grandstream GBX20 Features and Specifications:
4.3 inch (272×480) TFT color LCD. 20 per page (each module contains 2 pages, for up to 40 lines per module. Combine up 4 daisy-chained modules for 160 contacts/extensions. BLF, call park /pick-up, speed-dial, presence, intercom, voice conferencing transfer/forward and more.