Features: - A perfect item for protecting your family from the dangers of carbon monoxide. - This alarm is highly recommended to be mounted on a wall surface Compact, lightweight & easy to operate. - Displays the level of carbon monoxide the unit is sensing. - Green LED: Flashes every 30 seconds to indicate the unit is operating properly. The green LED will also flash before CO reading is taken and when any button is pressed. - Red LED : When a dangerous level of carbon monoxide is detected the red LED will pulse and a loud alarm pattern will sound. - Test/Reset button is designed for weekly testing if it works properly and reset the unit during CO alarm - Alerts users when batteries needs to be replaced - The carbon monoxide alarm pattern is 4 short beeps, followed by 5 seconds of silence, followed by 4 short beeps with a corresponding red LED flash. This cycle will continue for 4 minutes and then change to 1 cycle every minute until the device is reset or the CO is eliminated. Specifications: Color: White Sensor: Electrochemical CO sensor Sensitivity/Alarm Time: Within 60~90 minutes at 50ppm CO concentration; Within 10~40 minutes at 100ppm CO concentration; Within 3 minutes at 300ppm CO concentration LCD Displayer (optional): 4 digits LCD displayer Standby Current: <50A Alarm Current: <50mA Standby Mode: Green Led flashes once every 30 seconds Alarm Mode : Red Led quickly flashes 4 times with unit chirping every 5 seconds, then repeat, Low-bat Indicator: Chirp every 30s as battery lower than 3.3V with green LED flashing and Lb on LCD Mal-function Indicator: Chirp every 30s with green LED out and Err on LCD Size: 10 x 4cm Powered By: 3 x AA Batteries (Not included) Power consumption: 0.3mW Package Includes: 1 x Carbon Monoxide Alarm 2 x Screws 1 x English User Manual