OpenVox G400E3 4 Port GSM PCI-E card with 3 GSM Module Modular Design for GSM channels Up to 4 Simultaneous GSM Calls (Per PCI-E Slot) enables full flexibility to traditional telephony systems to go GSM network IMEI and PIN modification works with Asterisk, Elastix, PBX in a Flash, trixbox and IPPBX/IVR projects