Apollo SA5150-750APO Soteria UL Multi-Criteria Detector Smoke and HeatThe Soteria UL Multi Criteria Detector (Smoke Heat) is Apollos most advanced detector offering suitable for a wide range of applications. It uses Purelight high tech smoke sensing technology to detect smoke particles entering the chamber and is fitted with two thermistors for detecting heat. It can be switched to detect smoke, heat or a combination of both, offering greater flexibility, fast detection and advanced false alarm management.