Snapalarm. Fiendishly clever Swedish smoke alarm that you install simply by snapping it into place around a light cord. Around SEK 349.00 (£23.00).
The unique feature of Snapalarm is its patented installation technique. You simply place the alarm in the cord of a pendant lamp with a click. No need to drill holes. It fits most cords, chains and rods, up to 2 cm. And it looks good! Remember! Place Snapalarm high up and in a central part of the room