Protect and monitor your vacation home, cabin or cottage even when you can't be there! Doing so is now easy and convenient with the new and improved Sensaphone 800, a remote residence monitoring system that can help you detect problems before they turn into disasters. Like the classic Sensaphone this new system will call you by dialing up to eight phone numbers when its sensors detect abnormal conditions (i.e. temperature dips or spikes, leaking water, intrusions, etc.). But the Sensaphone 800 takes remote monitoring one giant leap forward with the added ability to control the thermostat by phone. Now you can set the temperature hours before you arrive, ensuring that the house is comfortable and cozy from the moment you walk in the door. While the Sensaphone 800 comes with a plug-in AC power supply, six size "C" alkaline batteries (not included) are required for battery backup.