Viper - Passive Infrared Motion Detector Compatible with Viper home monitoring and security system starter kits - For use with your existing system. Utilizes PIR (passive infrared) technology - To continuously scan your home and detect unauthorized movement from up to 39.4' away for efficient monitoring. Real-time reports can be sent directly to your enabled mobile phone to keep you apprised. Multizone spherical lens - Features a 90 horizontal and a 105 vertical coverage area to easily detect motion within a broad expanse. Sealed optics minimize false alarms due to external light, pets and insects. Built-in tamper alarm - Alerts you when the unit is tilted. Battery-powered (requires 2 AA alkaline batteries, not included) - For simple wireless operation. Up to 3 years of battery life ensures long-lasting