A set of three stackable coffee mugs from the Fire King line by Anchor Hocking. The mugs, 2 green and one yellow, measure 4" wide including the handle and 3 1/2" high. The bottom is impressed with "Anchor Hocking Fire King Overproof 63 Made in USA." The condition is good, with some minor scuffing due to use but there are no cracks or chips.
Fire-King was produced by Anchor Hocking Glass Corp. of Ohio from 1942-1976. Made of low-expansion borosilicate glass, Fire-King products were durable and cheap to produce. They were often given away as promotional and advertising pieces at grocery stores and restaurants. It is not recommended that you put your Fire-King in the dishwasher as the heat and harsh soap can render the fired-on graphics and colors cloudy and dull. Fire-King was created before the use of microwaves, and although the glass can withstand high temperatures, please use your own discretion.