Carrie Coon Reveals Her Neck-Saving Hack for 'The Gilded Age' Cast

Carrie Coon is giving her "The Gilded Age" costars a little support ... and we're not talking about emotional support.

We caught up with the actress at LAX Friday, where she revealed she's been handing out special neck rests to the women on the HBO series ... all thanks to those massive period-piece hats and elaborate wigs.

Carrie whipped out one of the devices, called a Cranial Cradle, and showed us how it works ... explaining it lets the ladies lie down without crushing their fancy headwear.

And it sounds like she's pretty sold on the contraption, telling us it works on planes and even against walls.

Of course, Carrie couldn't resist taking a little jab at the airline industry ... pointing out plane seats are built for men ... just like everything else.

As for where fans can snag one, Carrie says they're available online ... joking she just gave the company some free advertising.