The Microwave RTE sensor (SD-R400-BQ) features 12~24 VDC operating voltage, 24.150GHz microwave Doppler technology, 10-ft. sensing range (adjustable) and adjustable relay output time. Its small size allows for a wide range of applications. Because it is universally compatible the sensor can be installed above automatic doors for no-touch ingress/egress and more consistent detection in large areas and over a wide range of temperatures. It is designed for indoor use only.