I saw those in the Skymall catalog!
I was going to, one of these days, show them off in class. but you beat me to it.
It’s actually some sort of glass/ceramic. It just looks like a red Solo cup.
They sell them at a little shop downtown here. I am getting them for my lake gifts to my SIL for having us up for the day. I always find something to take. They have beer looking ones and wine ones, too. I laugh every time I see them.