The LHi 968 pyroelectric infrared-detector series is specially designed for
Intrusion Alarm  applications . It includes a dual element pyroelectric ceramic
with FET in source follower connection and  RF protection by a resistor and
additional capacitor.
This detector is available in TO-5  housing with an infrared filter which protects
the elements from strong white light disturbance. It offers  high responsivity
with excellent common mode performance (match) and low noise