20 Button Extension Module

The Grandstream GBX20 is a professional IP phone extension module designed to simplify call handling in busy business environments. Featuring a 4.3-inch colour LCD display and 20 programmable keys, it expands the functionality of compatible Grandstream IP phones. Ideal for receptionists, administrators and high-volume telephone users, the GBX20 makes it easier to monitor extensions, manage incoming calls and improve communication efficiency.

Expand Your Call Management Capacity

The GBX20 provides 20 programmable keys per page, with two pages supporting up to 40 contacts or extensions per module. For larger installations, up to four GBX20 modules can be daisy-chained together, providing access to 160 contacts or extensions. This scalable design allows businesses to expand call handling capabilities without replacing their existing compatible Grandstream IP phones.

Clear Display and Convenient Call Control

The module features a 4.3-inch (480 x 272) TFT colour LCD with 20 dual-colour LED keys and two page navigation buttons. Users can quickly identify extension status and access frequently used call functions. Support for Busy Lamp Field (BLF), speed dial, call park and pickup, presence monitoring, intercom, conferencing, call transfer and forwarding helps staff manage calls efficiently.

Compatible with Grandstream IP Phones

The GBX20 is designed for use with selected Grandstream devices, including the GRP2615, GRP2624, GRP2650 and GRP2670 carrier-grade IP phones, plus the GXV3350 and GXV3450 IP video phones. This makes it a practical upgrade for compatible business telephone systems where additional programmable keys are required.

Simple Installation and Management

The GBX20 connects to a compatible host phone using the supplied USB cable and extension connector hardware. A single module can be powered directly by supported host phones, while installations with two or more modules require an additional 12V power supply. Configuration is managed through the connected IP phone, helping installers simplify setup and ongoing maintenance. Firmware updates are also managed through the host phone.

Flexible Business Telephone Expansion

Combining programmable call controls, clear visual monitoring and expandable capacity, the Grandstream GBX20 extension module is an ideal accessory for reception desks, office administrators and businesses handling large volumes of telephone calls.