Does anyone have any recommendations on 3inch and 3.5inch frames for the O3 air unit?

Looking for a relatively durable frame for freestyle

Of the 3 and 3.5" frames I've tried I'd say the Quadmula Siren split fits the durable attribute. I still have my o3 in an AOS3.5-o3 but I wouldn't say that's durable in comparison. From Quadmula you can choose TPU plates meant for the o3 and they also give you the screws to thread into the o3. Hopefully they'll start making it in a 3.5" option. Been real happy with an o3 in a 5" split.

I've been looking at these, but not for O3 use.

https://yourfpv.co.uk/product/volador-vx...frame-kit/

what are the requirements, is it 20x20mm mounting diameter? whats the hight of the unit?

I had this issue when looking for a 5” frame that would accommodate my HDzero freestyle vtx AND a 30x30 stack.. Some great frames out there.. you may have to be creative with component fitment and mounting..
I’ve got a whoop board in my Tinyhawk freestyle. And mounted a30x30 fc in the front of a fpv glide frame..
Just because there are no mounting holes that “fit”, doesn’t mean you can’t make it fit..
Find a frame u like, and try to make it happen..

I like the Siren Split and although I don’t have one or 03 air unit this video got my attention.

  

Funny, I remembered Bacon Ninja recommended the same frame on 6S!