Are domes interchangeable?

I am wondering if a 6mm Oticon brand open dome will fit on my Phonak Solanas? The Phonak 5mm is a little small and the 7mm a little big.

I don’t think so. I am fairly cerrain that the phonak receiver end is smaller than the oticon one.

I use Phonak “closed” domes (actually, they have two small vent holes) on my Oticon AGIL HAs… No problem. See my “Disappointing Day” thread posts in “Digital HAs” sub-topic for explanation of why I prefer these for my particular circumstances.

This. The Oticon receiver is about 4mm across, while the Phonak one as about half the size.

Yes, the Phonak receivers and wax guards (i.e., the first thing the domes fit over) are smaller in diameter than the Oticon receivers and wax guards. But the domes are highly elastomeric, and the Phonak domes fit over the Oticon wax guards and receivers…no problem.

Per other posts, I use Phonak domes on my Oticon HAs because they work much better for my particular circumstances and preferences.