My sweet husband is a NASA nerd and a big guy.  I went to the NASA site to order him a shirt for Christmas (one of the three things on his list), but they didn't have anything larger than 2x.  Good ole Amazon, had a seller for me.  I wanted a quality shirt, not a cheap knock off with a NASA logo.  This shirt is high quality, plenty of room allowed for shrinkage over repeated washings (this will last him for years)and he LOVED it.  He's happy, I'm happy.