The system works on the Cellular communication. Since Cellular service is available most everywhere, you are just a text away from your boat. Not only will you receive any and all alarm messages from your vessel, you can also request specific information as well. You can Text Message your vessel with “xxxx Battery #2 Voltage” and this system will respond back with whatever the voltage reading is. The “xxxx” in the message is your Passcode, where the vessel will not respond unless it knows it is you. The Passcode was implemented because you can also enable and disable inputs via Text Message as well, in other words no one is going to play a joke on you. Say you have a C02 detector that has reached its end of life. Well to prevent additional alarms from the C02 Detector until you replace it, you can send “xxxx Disable Fume #2” to silence the alarm until further notice. There is a whole list of commands that this system will respond to. This system currently only works on the GSM Network (AT&T, T-Mobile, Verizon, ect), unfortunately it does not work on CDMA Networks (Sprint, Boost, ect). It requires a SIM Card, which we can provide, or one can be purchased through places like Target, Walmart, T-Mobile and others.