Originally developed for military applications in World War ll as ballistic missile nose cone material, Corning Ware's Pyroceram also proved effective in bakeware in the home after the war. This glass-ceramic, non-porous material was capable of withstanding sudden temperature changes and was resistant to stains and odors. This same dish could be used for cooking, freezing and serving food, a boon to cooks looking for cooking shortcuts. From what I have read on the Corning Ware 411 blog these items was produced 1961-66 and Corning Ware production started in 1958. Was used as a reference(very informative articles) Please see all 12 photos taken for best description.Dish is Very Good-Excellent Condition with a scuff on bottom and a utensil mark beside 1 handle/Lid looks good but shows general usage and an air bubble beside the P.