Thanks just ordered 5? Sets.
Don't forget these are only a 10 year investment so you'll need to change them all when that time comes.
Yep there's two versions, the battery only version, which has 6 batteries in it and the batteries last ~5 years and a mains wired version that contains only 3 batteries (so it still works during power cuts).
So you get 2 versions? Wired and non wired?
True, but personally I would pay a bit extra for hassle free returns, but I will add it in the description so that the people have all da facts.