These detect any unauthorised body-heat movement within an area, incorporating intelligent digital signal processing (DSP) and Dual Edge Sensing (DES) technologies. These detectors have been developed to virtually eliminate false alarms yet still provide maximum security. The Advanced Wireless Supervision (AWS) technology constantly monitors battery and tamper conditions. An innovative swivel bracket design allows for a quick and simple installation. With the power saving mode and lithium batteries the detectors will give you an extended battery life of approximately 3 years. The system will automatically let you know when the sensor batteries require replacement, or if the sensors fail to communicate.