The GSMVLP5-4G is an optional communication module intended for use with Lynx Touch Wireless Alarm Kit controls, and provides wireless communication with the AlarmNet network for backup delivery of alarm and other messages to the monitoring central station. It also supports voice communications between the control panel and the Central Station. This communication module transmits signals via the AlarmNet-G network (GSM cellular network), using GPRS and forwards them to your Central Station. If the GPRS network is unavailable, the GSMVLP5-4G will attempt to send the transmission via SMS.