The PDX-PMD75 is an Alarm Motion Detector from Paradox. Its precision digital analysis, two separate infrared sensors and unique pet-friendly lens detect intruders with absolute accuracy while ignoring pets up to 40kg (90lbs). Its outstanding detection and false-alarm immunity give you unmatched reliability and stability. The Digital Dual-Optic PIR is a dual-element sensor which provides pet immunity for animals weighing up to 40kg.