2W-B SYSTEM SENSOR I3 Smoke Detector 2-Wire Photoelectric With BaseThe System Sensor 2W B is an i3 Series conventional, two wire, photoelectric smoke detector. Add the hardwired 2W B smoke detector to most existing alarm system control panels. The 2W B smoke detector is not the typical conventional detector. In fact, the 2W B is a System Sensor i3 series intelligent detector that includes many of the same features found in analog smoke detectors. Drift compensation and smoothing algorithms, standard on the 2W B,