Save money by passing on a full security system and installing the Skylink Wireless Security AD105 Emergency Dialer and Panic. The Emergency Dialer sends your personalized emergency voice message to preprogrammed phone numbers. When you have an emergency, just hit the Panic button on your included transmitter, and the Dialer will immediately send your emergency message to the phone number you choose. Let family, friends, or authorities know when you need help at a moment"s notice. The Panic Transmitter conveniently fits on any keychain or necklace. It allows you to activate the Dial-Alert at a distance of approximately 100 feet from the dialer. The transmitter is water resistant and shock resistant, allowing you to carry it wherever you go. Rolling Code Technology: Every time you press your remote transmitter to turn the security system on or off, a code is generated which is recognized by the receiver that in turn performs the desired function. With most security systems, there is only one assigned code. Whenever the remote is pressed, it generates the same code, making it vulnerable to code grabbers who use electronic scanners to steal the code. With rolling code technology, each time the remote is used, it generates a different code.