SAFE-TECH Interlinked Carbon Monoxide Detector places the highest priority on safety. Also, this alarm meets the British standard for CO Alarms, BS EN 50291-1:2018. Additionally, this alarm is tested to meet UKCA and CE standards. This detector has an advanced electrochemical sensor. Therefore, it detects even the smallest rise in CO levels, giving a quick response to potential CO poisoning. Also, this detector has a 10 Year tamper-proof battery. Lasting for 10 years and guaranteeing continuous protection. This Interlinked Carbon Monoxide Detector is compliant with the latest Scottish Legislation. Making it Suitable for any room that has a carbon-burning fuel appliance. CO alarm density is as follows : 50ppm alarm does not activate, within 120 minutes. 50-100ppm, an alarm within 80 minutes. 100-300ppm, an alarm within 30 minutes. 300ppm, an alarm within 50 seconds. * Battery life may vary based on configuration, application usage, and features. * We try to get you the best