Simplex 4098-9751 In-Duct Sensor Housing with RelayThe Simplex 4098 9751 in duct sensor housing with relay installs a 4098 9714 TrueAlarm analog photoelectric sensor directly in HVAC duct airflow for applications where sampling tube duct detectors are not appropriate. It supports 0 to 4000 ft min duct velocity, communicates on TrueAlarm IDNet or MAPNET II, and adds a programmable local Form C relay for fan shutdown, damper control, or other fire response actions. Key Specifications: Type: TrueAlarm in