Review on Valterra A10-3360VP Beige Rotating Heat and Air Conditioning Register with Damper (5 Inch Inner Diameter, 7/8 Inch Collar) by Tarrance Man

I bought these to replace the non-damping vents in my 21 Grand Design Imagine. The listing says they are 5" inside diameter and I wish I had read the other reviews because they are clearly 5 1/2" and will not fit in my camper without cutting big holes in my ceiling ( something that's not even in the realm of possibility). At first I thought they just sent me the wrong size, but as you can see from the attached photo, THEY DON'T EVEN MAKE 5" FANS! What a waste of time and energy, now I have to send it. So trust other reviews, not the advertised size, make sure your vents are 5 1/2 inches inside before ordering.