Siemens AD3-I

Model AD-3I and AD-3ILP Detectors from Siemens Industry, Inc. are System 3, System PXL, System SXL-EX, System SXL, System XL3, System CP-2ER, MXL Control Panel and MXL-IQ Control Panel compatible air duct detectors. They are designed for use in heating, ventilating, and air conditioning duct systems. Model AD-3I uses ionization smoke detectors, and Model AD-3ILP uses photoelectric smoke detectors to detect the presence of combustion products in a duct system.