... Monitor ,Voice Monitor ,Mini Wireless Sim Voice Monitor ,Mini Wireless Sim Audio Monitor ,Mini Sim Card Wireless Voice Monitor USB HUB + Audio Surveillance4 USB ... -saving, no trouble of extra cables and adaptersSpecificationPrimary Function: USB HUB with 4 ports and GSM sim audio surveillance functionGSM frequency ... ! and Look forward to seeing you then! 4-Ports USB HUB GSM Sim Card Monitor