feature: - The perfect item to protect your family from carbon monoxide. - It is highly recommended to mount this alarm on a wall Compact, lightweight and easy to operate. - Displays the carbon monoxide level being sensed by the device. - Green LED: Blinks every 30 seconds to indicate normal operation of the device. The green LED also flashes before taking a CO reading and when any button is pressed. - Red LED: When dangerous levels of carbon monoxide are detected, the red LED will flash and sound a loud alarm pattern. - Test/Reset button designed to test weekly if it is working properly and reset the device during carbon monoxide alarms- Alerts the user when the battery needs to be replaced- The carbon monoxide alarm pattern is 4 short beeps, followed by 5 seconds of silence, then 4 short beeps, and the corresponding red LED flashes. This cycle will last 4 minutes and then change to 1 cycle per minute until the device is reset or the CO is eliminated. Specification: whitecolorSensor: Electrochemical COsensorSensitivity/Alarm Time: Within 60~90 minutes at 50ppm CO concentration; Within 10~40 minutes at 100ppm CO concentration; Within 3 minutes at 300ppmCOLCD display (optional): 4-digit LCDdisplayStandby current :