This is a Hazel Atlas "Bonanza" mug. It is a famous steakhouse in America. It is milk glass, but *It is not Fire King. There is no mark. It is used. After purchasing it used, I only displayed it and did not use it. There are some scratches and dirt, but I hope someone who doesn't mind will consider it. As it has been stored at home, please refrain from purchasing if you are concerned about minor details. Thank you.