The wireless WNX-40IX Passive Infrared Sensor from Optex gives superior detection with high performance against false alarms. With an excellent tolerance to spot temperature changes from movements of blinds, curtains and nuisance animals, the WNX-40 uses OPTEX's patented Quad Zone Logic to accurately discriminate between humans and other sources of infrared heat. The WFX-40IX includes a built-in transmitter compatible with Interlogix & QOLSYS Wireless Systems.