AW-BK901 Series Infrared Linear reflex beam smoke detector, designed for fire preventive in the open area, is a long interval one, Protective area : The maximum is 1400 m2 (14x100 = 1,400 m2) and the maximum width is 14m. Order information 25, 40 meters with 1 reflector, 70 and 100 meters with 4 reflectors