Sold Out 09|Telephony|VoIP Phones|Expansion Modules Grandstream Expansion Module for GRP2615,GRP2624,GRP2650,GRP2670,GXV3350,GXV3450 GS-GBX20-EXT R3,415.34 (Incl. VAT) Sold Out GBX20 20 Button Module, 2-pages. 40-lines per module, up to 4 modules View