Models CR-135MP, CR-165MP, CR-165MP, and CR-200MP
These models are dual-action types that will respond to a rate of temperature increase at the ceiling of 15º Fahrenheit degrees per minute (8.4º Celsius degrees per minute). These detectors will also respond when the fixed temperature (non-restorable) threshold is exceeded. Dual-action detectors are installed in areas where rapid fluctuations in ceiling temperatures are not expected.