I have one of these love it! If you're from the UK get it straight from the maker, must be the cheapest version, although on search I did notice Iwantoneofthose stock it too ...
I got mine at < link removed >
Don't have any problems with it coming off of the key but I do keep mine in my handbag all the time mostly find it a tight fit though and I have too bought one for my whole family,
we're all space saving geeks
