Yale HSA6021 Alarm Accessory Pet Friendly PIR, Motion Activated, Accessory for HSA Alarms The Yale Pet PIR Motion Detector Sensor for HSA Alarms 433MHz HSA6021 is a state-of-the-art security device designed to protect your home while accommodating your furry companions. This advanced motion sensor uses passive infrared (PIR) technology to detect movement and trigger alarm systems, ensuring enhanced security for your premises. Enhanced Security: The 433MHz frequency used by the sensor ensures a secure and reliable connection with compatible HSA alarm systems, providing comprehensive protection for your home. Passive Infrared Technology: The motion sensor utilizes passive infrared technology to detect heat and movement within its range, making it highly effective in detecting intruders and potential threats.