Crib Mobile Help - cant find one that fits our railing

Summer

I am having a very hard time finding a crib mobile are that fits our crib side. The side of our crib does not have slats that go all the way up. And the top railing part is thick. Most arms I've found require it to be placed between the slats.

I know they are not used after 5/6 months anyways but I still would like one.