I don't own one (I borrowed one, from a good friend) but I think it is the one you are referring to as adjustable, with the "hinged" arm so that it fits various diameters of adjuster nuts.
My advice would be not to get this type. A real curse-fest using the thing, as it keeps slipping off and must be re-positioned for every single turn of the adjuster.
I would recommend spending the money on good ones which are of a fixed-size and matched to the size of the adjusters that you have. -Rob
