The TRANS?DUO occupancy sensor is a new member of TRANS sensor family combines digital Passive Infrared (PIR) & state?of?the?art High Frequency Doppler (HFD) sensing technologies in a low profile housing to provide second?to?none occupancy sensing performance for today's sustainable buildings. TRANS-DUO inherited the interchangeable lens from the TRANS family building sensor concept of "Interchangeable EMO".