The RWM90 replaces the RWM50 and RWM100 as the entry-level model. The optical smoke detector triggers an alarm as soon as smoke particles enter the measurement chamber. It covers up to 40 m² within a room and warns loudly with 85 dB of the dangerous smoke gases. Thanks to the user-friendly, large test button, the smoke detector can also be easily tested in high rooms. A decrease in battery voltage is indicated by an acoustic signal.