Skylink H-2, Long-range Alert Kit with 1 Motion Sensor and 2 Receivers; Be Notified of Your Surroundings. Alerts you when motion is detected surrounding your garage, home or business 2 in 1 Alert & Alarm Modes. Be notified of your surroundings! Supervised sensor monitors the sensors and their battery condition automatically Motion detecting range 40-Feet:Operating range up to 800-Feet ; easy to set up Expandable system, add on various other sensors such as Door/Window sensors, Garage Door sensors and