The GBX20 is an Extension Module that adds functionality, versa tility and flexibility to Grandstream’s GRP2615 Carrier-Grade IP Phone and GXV3350 IP Video Phone. It f eatures a 272x480 LCD display that offers up to 40 contacts per module with support for up to 160 contact s by using 4 modules. The GBX20 supports a wide-range of advanced call features including BLF, call park /pick-up, speed-dial, presence, intercom, voice conferencing transfer/forward and much more. An ideal sol ution for businesses and receptionists managing high call volumes, the GBX20 ensures maximum productiv ity by efficiently monitoring and dispatching incoming calls.