This is an Anchor Hocking Fire King sapphire blue “Philbe” D-handle mug. This pattern was produced from 1941 until 1956.
I have three (3) of these mug for sale, each one separately. They are all in excellent condition. I did want to bring to your attention the fact that there are bubbles in the glass. You will see these in the photos.
Take a look at the photographs, and if you have questions, please e-mail.