I'm not too up on this kind of thing but it seems a good deal. You know the jobbies, plug them in and they squirt out some air freshener every hour and you get to choose the intensity level from 1-5. You get two 20ml fragrances with the plug.
They normally cost £8.20 so a good saving right there. The refills are £5 or 2 for £6 so you're probably better of buying the whole thing at the moment.
I think it's just the two available at the moment, I wont go into further detail because i'm a bloke and dont want to talk about Cherry Blossom and Water Lily etc
Hope this helps someone. Bought from the Cannock store but is online so should be available everywhere.