The bi-directional IRP-9ZBS passive infrared motion sensor provides quality detection with pet immunity up to 27 kilos (59 lbs). Adaptive Digital Signal Processing (ADSP) algorithms are employed to effectively reduce false alarms. With its advanced authenticated two-way encrypted wireless link (2.4GHz DSSS), the IRP-9ZBS guarantees excellent communications range and successful signal transmission. This easy-to-install sensor is powered by a lithium battery with battery life lasting more than 4.5 years.