Aico Ei208W Co2 Lithium Battery Alarm Radiolink Upgradeable. Aico Are The Leading Manufacturer Of Residential Fire And Gas Detection Devices In Europe. This Means You Know You Are Getting A Quality And Reliable Product When You Choose Aico. The Aico Ei208W Is A Battery Powered Carbon Monoxide Alarm. It Has A Proven Electrochemical Sensor To Detect Any Carbon Monoxide That May Be Present. There Is Also A Large Test/Hush Button. The Test Is Activated If The Button Is Pressed And Held, Which Causes The Horn To Sound, And Hush Mode Is Activated If The Button Is Pressed Briefly And This Sends The Alarm In To A Ten Minute Period Of Reduced Sensitivity. It Has A Memory Feature Which Indicates Whether Or Not The Alarm Has Been Previously Activated. The Alarm Is Powered By A Sealed In Lithium Battery And There Is An End Of Life Indicator, Which Notifies You When The Fitting Is Coming To The End Of Its 7 Year Life.