Lady I'm dealing with today and tomorrow has asked me about mains smokes. She wants one in EVERY room in the house, and on the landings and even in the cellar. She's a tad paranoid about fire I think. She also wants the smoke alarms to detect carbon monoxide. I've seen battery combo detectors but does any company make mains interlinked ones? Or at least a carbon monoxide alarm that can interlink with the smokes?