System Sensor YD4120 For Smoke Detector Duct Application. Used W/o Clear Shield

System Sensor D4120 Smoke Detector for Duct Application, Black "E3D"

System Sensor D4120 Photoelectric Duct Smoke Detector - Condition Unknown As Is

System Sensor D4120 Smoke Detector for Duct Application, Black "D3E"

SYSTEM SENSOR D4120 Duct Detector Unit Tested Ok

System Sensor D4120 4 Wire Photoelectric Duct Smoke Detector

System Sensor D4120 Smoke Detector for Duct Application, Black "U2D"

System Sensor D4120 Gray 4-Wire Photoelectric Duct Smoke Detector - For Parts