Built-In 10-Year Battery: This CO detector features a sealed lithium battery that offers 10 years of continuous power, eliminating the need for frequent battery replacements. Additionally, it can be turned off when not needed to conserve battery life. Dependability & Precision: Certified by UKCA and compliant with EN 50291 standard, this reliable CO alarm can precisely measure carbon monoxide levels in ambient air. In the event of a potential hazard, it immediately sounds a loud 85-decibel alarm to warn your family. Real-Time LCD Display: The spacious LCD display provides a persistent and unmistakable view of CO levels, even when they are at zero. Its built-in backlight guarantees visibility in low-light conditions, facilitating seamless and round-the-clock monitoring. Intuitive LED Indicators: The CO alarm is equipped with 3 LED indicators that provide clear information about its working status: a green LED flashes once every 60 seconds to indicate normal operation, a red LED