Specification: 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 Audibility: 85dB ( at 3m distance ), Frequency 3 - 0.5KHZ 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 Powered By: 3 x AA Batteries (Not included) Color: White Materials:Plastic Size:As pictures show(1 inch = 2.54cm) Description: 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. 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. 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 This alarm is highly recommended to be mounted on a wall surface Compact, lightweight & easy to operate Packing Content: 1pc Carbon Monoxide Alarm Note: Please be aware that due to your computer monitor display the color may have some difference between the picture and the real item. There is 2-3% difference according to manual measurement.