I'm not at home at the moment. But I will be there tomorrow. Then I can check it out and let you know. Sorry I didn't respond sooner. I am out of town at the moment. My Father In-Law had emergency 6 heart bypass today. I will be home in the morning and can give you the answer then. Thank you for asking :) Have a great evening :)
In reply to helpfulnany - Not stamped that I could see. This is the information on this product. Product Description- This glass mug was manufactured and sold through Tiara Exclusives, Humpty Dumpty - pattern #246. Indiana Glass produced several child's set of nursery rhymes glass sets. The amber child's set, (plate, bowl, cup, and tumbler) was produced beginning in the late 1970s and discontinued in the mid 1980s. This Auction Is For The Cup/Mug ONLY. Thank you for your question :) I hope I answered it for you :)
Dimension - 3 1/2 inches tall and 3 inches in diameter at the rim