1, Battery  compartment on alarm  top surface, battery replacement is very convenient;
2, Could be installed in motor homes, ships etc. quavering places;
3, Advanced photoelectric sensing technology; detects visible particles (associated with  smouldering fire) sooner than ionization alarms
4, Auto  check  malfunction.
5, Test  button;  tests  unit’s  electronic  circuitry,  buzzer  and  battery  function Sensor type: