FH wedding ring

My FH ordered his wedding ring online, because it was a ton cheaper.

He got a simple comfort fit platinum band. The problem is we can't figure out if it fits. From what we've read online, the comfort fit does come off easier. It won't come off if he shakes his hand hard or washes his hand, but it can move a little bit below the knuckle.

We have 30 days to return it so not sure what to do. He already went down a size from what he normally wears because the comfort fit runs big.

How tight are your FH's rings?

Where you got the ring, do they do quarter size or half size down? Do they have ring sizers they could send you or can you go to a store that has comfort fit rings and try one on for size?

best time I think to try on a ring is when its cold since the finger shrinks, but then remember it swells in the heat, you don't want it too tight either!

It definitely should not move below the knuckle, that's scary.