Check the listing for details. Simplex 4098-9756 Duct Detector - Same Day Shipping (SEALED). Condition: New. Listed at 145.40 USD. Simplex 4098-9756 | Duct Sensor Housing | Same Day Shipping (SEALED BOX) SIMPLEX 4098-0030 Simplex® compact air duct smoke sensor housings provide TrueAlarm operation for the detection of smoke in air conditioning or ventilating ducts. Sampling tubes are installed into the duct allowing air to be directed to the smoke sensor mounted in the housing. Compact air duct sensor housing with clear cover to monitor for the presence of smoke** Includes factory installed TrueAlarm photoelectric smoke sensor and features: * Individual sensor information processed by the host control panel to determine sensor status * Digital transmission of analog sensor values via IDNet or MAPNET II, 2-wire communications * Programmable sensitivity, consistent accuracy, environmental compensation, status testing, and monitoring of sensor dirt accumulation