... Led Indication CY-858-3 personal co detectorTechnical Parameter Operating voltage DC 9V Sensitivity & Time 50ppm, alarms within 60~90 minutes 100ppm ... , alarms within 10~40 minutes 300ppm, alarms within 3 minutes Standby Current ... is out.).- Alarm memory feature: If the unit ever alarms, pressing the button, red LED will flashes once every ...