Using Sergio Angeriz's excellent design as a starting point,

https://www.printables.com/social/93377-sergio-angeriz

I modified the iPhone holder to mount under my iMac. I am not sure what computer models it will fit. Mine is a 24' iMac “M1” from 2021. The iMac base is approximately 130mm wide and 6mm tall. Also, my phone is a iPhone 14 Pro with a case. I believe an iPhone Max will fit as long as you don't have the monitor angle straight up and down. I laid the phone angle back a few degrees from the original model to allow the phone angle to match my preferred computer screen angle. I am sure lots of different types of phones will fit as spacing generous. It's a good fit, however if you'd like it to be rock solid, I recommend using a tiny bit of Blu-Tac / Fun-Tak. https://a.co/d/bMi0A7v

Phones 13mm or thinner should fit well.

God Bless,

Casey