This is a beautiful, white, oven-proof stacking mug from Fire King by Anchor Hocking. This is a durable, sturdy every-day mug designed for use in restaurants. It features a thick "D" shaped handle and a ribbed design around the mug's foot.
Material: Opaque white oven-proof glass
Markings: Anchor Hocking, Fire King, Oven-proof, #21, Made in U.S.A
Measures: 3 1/2" (8.89 cm) H x 4" (10.16 cm) W Opening: 3" (7.62 cm)
Condition: Excellent vintage condition. No chips or cracks. Little to no wear.
Date: Estimated to the late 1970's