From what I can see the smallest safefill is 8.5l and that cylinder is 396mm high - exactly the same size as the height of the locker - I presume the dimentions autotrail give are external so that one won't fit - although width wise it would have been fine - shame they couldn't have squeezed an extra 1cm height to have the option...I was actually thinking of the width of the locker so that you could get two of the shorter Safefill bottles in.