This optical smoke alarm is compact and simple, with a non-replaceable, sealed-in Lithium battery for 10 years of continuous protection - meaning the battery will never need to be replaced. It has an end of life notification to alert you once 10 years are over and its time to replace the alarm. It also has a combined test/ hush button which allows the alarm to be tested and also temporarily silence nuisance alarms.
Kitemarked to BS EN14604:2005.