A:AnswerMy iPhone 7 is in an Otter box. Works just fine. Not sure about the belt clip though. I’d say that if the clip is thinner than 1/4-inch or so, it should work.
A:AnswerThis is a solid-built dash or windshield mounted holder that has a sticky gel on the suction cup and quality- made parts that don't vibrate around when driving. If you properly mount this on a dash pad or a windshield, it will not fall off - ever.
Oh, and it doesn't come with a cd player slot attachment anyway.