System Sensor D4240 4-wire photoelectric low-flow duct smoke detector

• Make: System Sensor
• Model code: D4240
• Type: Smoke

System Sensor D4240 is a 4-wire photoelectric low-flow duct smoke detector. It features a pivoting housing that fits both square and rectangular footprints and mounts to round or rectangular ductwork. A plug-in sensor head offers improved false alarm immunity and simple installation, testing, and maintenance. An improved cover design isolates the sensor head from the low-flow feature for simple maintenance.