Battery-powered and built-in carbon monoxide sensor makes it safe to useTest/reset button to verify proper unit operation and reset the unit during CO alarmGreen and red LED lights that indicate normal operation and alarm statusLow voltage warning and end-of-life timer and EN50291 compliantSpecifications:Model: JKD-602Sensor: Electrochemical CO sensorAlarm Concentration: 50(+/-30%)ppmSensitivity/Alarm Time: 50ppm, Alarms within 60 to 90 Minutes100ppm, Alarm within 10 to 40 Minutes300ppm, Alarms within 3 MinutesStandby Current: 35AAlarm Current: About 20mAAlarm Sound: 85db ()Power Supply: 3*AA Batteries (not included)Operation Ambient Condition: 0 to 40 Centigrade, 20 to 95% RHMounting Type: Wall/Ceiling mountColor: WhitePackage Includes: 1 x Carbon Monoxide DetectorNote:Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.