Alarm Standards: Smoke and carbon monoxide detector, alerts at different levels of carbon monoxide concentration - < 50 PPM, no alarm, the LCD screen displays the concentration; 50 PPM-100 PPM, alert within 80 minutes; 100 PPM-300 PPM, alert within 30 minutes; 300 PPM, alert within 3 minutes. Easy Installation: Carbon monoxide detector provides continuous monitoring of carbon monoxide levels to ensure the safety of your family. It operates on 2 x 1.5V AA batteries (not included) and requires no wiring, allowing it to detect even during a power outage. Highly Sensitive and Responsive: Carbon monoxide detector, equipped with a built-in carbon monoxide detection chip and an electrochemical sensor, can detect odorless, invisible, and deadly carbon monoxide in the air. Reacts quickly to protect your life at the first sign of fire danger. Simple to Use: Carbon monoxide detector features a single test/reset button. When dangerous levels of carbon monoxide are detected, the red light flashes