Grandstream GBX20 Extension Module enhances your GRP2615 Carrier-Grade IP Phone or GXV3350 IP Video Phone with expanded call management capabilities and improved productivity. Featuring a vibrant 4.3 inch (272 x 480) TFT color LCD and 20 dual-colored programmable extension keys per page, it supports two pages per module for up to 40 contacts.

You can daisy-chain up to four GBX20 modules to monitor and control up to 160 contacts or extensions, making it ideal for receptionists, call centers, and busy office environments. The module offers advanced call control features including Busy Lamp Field (BLF), call park and pick-up, speed dial, presence indication, intercom, voice conferencing, call transfer, and forwarding.

Integrated arrow keys allow easy navigation between pages, delivering a user-friendly interface to efficiently manage multiple lines and features. Designed to seamlessly integrate with compatible Grandstream IP phones, the GBX20 guarantees enhanced flexibility and scalability in handling high call volumes.

For more details and support resources, visit the official [Grandstream GBX20 product page](https://www.grandstream.com/products/ip-voice-telephony/extension-modules/product/gbx20-extension-module).