These covers have, as you would expect, an elasticated edge to assist in pulling the cover over the wheel and keeping it in place. My pair had one that went over the wheel easily and the other is a real strain. This is not good when you are struggling to cover your wheels after a very muddy game of golf and you are tired. I have rejected them and now gone to the expense of buying a proper, full sized trolley bag which makes life so simple. The other main problem is that the manufacturers seem to have forgotten that most trolleys these days have 3 wheels and here you only get two. Pointless really.