'Free carbon monoxide alarm' with details in Tuesday's (7 Jan) copy of the Daily Express worth £29.99 (in partnership with British Gas).
Full details, T&Cs on pages 31-34. Online subscription. Registration required. Subject to availability. Allow 28 days for delivery. 5000 units available on a 'first come, first served basis'.
Direct link: http://www.britishgas.co.uk/express
Carbon Monoxide is a highly poisonous gas that is very difficult to detect as you cannot see, smell or taste it. You may not be aware of its presence until it's too late