The Grandstream GBX20 is an extension module designed to expand the communication capabilities of compatible IP phones, including the GRP2615, GRP2624, GRP2650, GRP2670, and GXV3350 or GXV3450 models. It features a 4.3-inch TFT color LCD with a resolution of 272x480 pixels, allowing you to manage up to 40 lines across two pages, with 20 contacts visible at a time. This module simplifies office workflows by providing quick access to essential functions like Busy Lamp Field (BLF), speed-dial, and presence indicators, while also supporting call park, pick-up, intercom, and voice conferencing transfers. For those managing larger teams, up to four modules can be connected in a daisy-chain configuration to monitor a total of 160 extensions. Measuring 210 x 124 x 33.5 mm and weighing 360 g, the black unit is built for a professional desk setup and includes a 2500 mAh battery. The package comes complete with everything needed for installation, including the support, connection plate, screws, a USB cable, and a power adapter.