Product Description: Function: [Reliable Sensor, Clear Alarm]: The carbon monoxide alarm uses a highly sensitive electrochemical sensor. They continuously measure the concentration of carbon dioxide in the ambient air. The CO detector will sound an audible alarm if the concentration reaches the appropriate limit. A flashing LED usually attracts your attention. [Robust Sensor Operation]: The CO gas detector is made of a high-performance electrochemical sensor, which is high-quality, durable, sensitive and durable. The working temperature is 5°C/40°C and the suitable relative humidity is 20-90%. Features: LCD display shows the CO concentration: Carbon monoxide, a deadly respiratory poison, is always with you. I don't feel like it. The LCD screen can read and monitor the CO concentration at any time to avoid danger. Battery Operation: The CO detector uses replaceable batteries (2x1. 5V AA). Even more convenient, the built-in battery ensures years of operation. A beep every 30 seconds