HomeSafe's 1000 HS is equipped with all seven NOAA channels for maximum reception of local weather reports, as well as bulletins for severe weather and hazardous conditions (i.e., fires, toxic chemical spills, earthquakes, radiation leaks, CIVIL EMERGENCIES, ACTS OF WAR, etc). In the event of severe weather or any other type of hazardous situation, a warning signal is broadcast by NOAA and the monitor's "alert" is automatically activated-sounding a 90 decibel siren, a voice warning or flashing a visual red LED alert. There is also an accessory jack for keying add-on external alert devices such as strobe lights or pillow vibrators (sold separately). To add to its versatility, this durable, compact monitor fits easily anywhere and plugs into a standard 120 VAC outlet. A built-in jack permits powering the unit from any 12 VDC vehicle or boat. And, with its 9V battery backup system, it even operates during a power outage or outdoors. There is no monthly monitoring fee; this information is free to you 24 hours per day by The National Weather Service. (Same as Midland 74-109 or First Alert WX-27 plus battery for battery backup).   An external antenna may be purchased separately for fringe areas.