TO5 case PIR sensor type SDA02 has a built in FET. This is very sensitive and can be used to detect humans. This combination package contains the sensor and 2 different lenses (long rang and short range). See G18938 and G18939 listing for details. All pieces for a blowout price. Note: no spec sheet or data available from us -look up on internet. Package value if purchased individually is $4.87.