Yeastar 4G LTE Module provides 4G cellular data on SIM card, making the 4G LTE become the primary Internet connection for S-Series VoIP PBX . Supporting 3G/4G network standard, the 4G capable S-Series VoIP PBX can register SIP trunks and make SIP calls with high-speed built-in data. It is ideal for business needs like temporary locations, mobile offices, and places where fixed-line broadband is not available.