10 Year Life Carbon Monoxide Alarm,Digital Display CO Detector,Battery powered 【Unique Design】: Built-in carbon monoxide alarm, with LED display, electro-optical sensor, high consistency and stability, beautiful appearance 【AUDIO AND VISUAL WARNING】: When a dangerous level of CO gas is detected, a loud 75 decibel alarm beep sound and red LED flashes to effectively provide an instant alert signal [Alarm standard and LED display]: The alarm time depends on the level of carbon monoxide concentration. The carbon monoxide alarm display screen can accurately measure the carbon monoxide concentration and its concentration data. Carbon monoxide levels are between 000 and 999ppm. "LB" means the battery is low and needs to be replaced, and "Err" on the LCD screen means the unit, then talk to our service staff. 【Alarm Stardant&ENERGY】: 50ppm, 90min alarm, 100ppm, 40min alarm, 300ppm, 3min alarm. Battery: DC3V (2*1.5V AA battery power supply) (battery not included) 【Applicable places】: