Carbon Monoxide Alarm from Ei Electronics.
This alarm will sound before a healthy person feels any symptoms of CO poisoning. It has an advanced CO gas sensor for increased reliability. Batteries are included with this alarm and it has a test button plus an end of life indicator. This unit also carries a 5 year guarantee.
Carbon Monoxide is a colourless, odourless, tasteless toxic gas. It is produced by fuel burning appliances or vehicle engines. Mild doses can cause headaches, nausea and flu-like symptoms. Higher doses can cause collapse and death within minutes.
Ideally you should have a CO Alarm in every room that contains a fuel burning appliance.