Heiman HS2SA-5M - Smart Matter smoke alarm with photoelectric sensor, 85 dBA alarm, LED indicator, and up to 100 m wireless range The Heiman HS2SA-5M smoke alarm combines reliable early fire detection with modern smart-home technology. Its photoelectric sensor detects smoke from all directions. An intelligent dust self-learning feature adapts to changes in the environment, reduces false alarms, and ensures precise, early warnings.