Fire-Lite's SD355 and SD355T addressable, low-profile plug-in photoelectric detectors use a state of the art photoelectric sensing chamber with communications to provide open area protection and are used exclusively with the MS-9050UD, MS-9200UDLS, and MS-9600 Addressable Fire Alarm Control Panels. The SD355T adds thermal sensors that will alarm at a fixed temperature of 135F (57C).