This vintage Anchor Hocking Fire King stacking coffee mug features a playful blue polka dot pattern and is made of durable glass material. It has an impressed backstamp and is an original piece from the United States. Ideal for all occasions, this coffee mug is perfect for adding a touch of vintage charm to your decor. The production style of this mug is milk glass and it is a part of the Fire King product line. This is a must-have for any collector of vintage mugs and decorative cookware.