1,Temperature compensation 2,Microcontroller sifgnal processing 3,Front and back tamper protection 4,Unique waterproof OUTDOOR WEATHER PROOF PIR SENSOR/ DUAL DETECTIONSpecificationsFrequency: 10.525 GHzMicrowave detection based on Doppler conceptN.O. & N.C. relays switched at the same timeInstallation height is calibration free from 6 ft to 8 ft (1.8 m to 2.4 m)Pet Immune up to 33 lbs (15 kg) ...