They went on easily, they expanded to fit the roof of our car and we were able to get the roof box on and attach it securely to the bars. So I went ahead and purchased a blue one (which are normally very expensive) even though this is not the brand we use. I?m really glad I did. Im shocked to tell you these shoes are falling apart??Ive worn Birkenstock forever and they usually last years! I shopped around and couldnt find these on sale nor my size anywhere. Habe den Support angeschrieben, dieser kann mir jedoch auch nicht helfen, da die Garantie abgelaufen ist und verweist stattdessen an einen (nicht genannten) Drittanbieter, welcher meinen Kopfhörer evtl. later on I will try to post an update, to let people know if I had to get rid of it or not. Then I bought some for the glasses. Nice and clear field of view, and they are durable. Ive owned IEMs for years.