An extension module featuring a color LCD display and programmable shortcut keys that attaches to compatible Grandstream phones to provide an expanded call monitoring interface. It includes 20 main keys with arrow buttons for navigating up to 40 contacts/extensions per module, and up to 4 modules can be connected together for a total of up to 160 contacts/extensions. Supports advanced call features such as Busy Lamp Field (BLF), speed dial, call park/pick-up, presence, intercom, and call transfer, making it ideal for efficiently managing and dispatching calls in high-volume work environments.