Almost all IF saunas on the market are nnEMF boxes. Even the brands that claim ultra low emf are misleading their customers - I can't remember the specifics of how they are getting away with this claim, it could be they are still emitting a ton of dirty electricity or something like that.
Anyway from my memory and research there seems to be only two IF sauna manufacturers that are truly very low or zero EMF. And of course guess what, they are both double to triple the price of the other manufacturers 😒
I don't have the company names at hand but I can post them later if you're interested.