Vintage TUPPERWARE #1766 Ultra 21 Pie Quiche 9" Pan Dish Lid for Oven/Microwave This listing is for two pieces from the Tupperware Ultra 21 collection. These bowls do it all, from preparation, to cooking, to serving, to leftover storage. Ultra 21 is made of a lightweight heatproof material and can be used for baking in a conventional oven up to 450 degrees, safe for microwave use, freezer safe and can be washed in the dishwasher on the bottom rack. Not for use in broiler or on the stove top. All pieces nest neatly for storage when not in use. Tupperware Ultra 21 Quiche Pie Dish. 9" diameter × 1.5" tall. Mold #1766 Lid #1767-3 Ultra 21 is conventional oven and microwave safe.