Pyrex table saver. Designed by Lurelle Guild. Made by Corning Glass Works, Corning, NY, about 1940. 2010.4.207
http://www.cmog.org/artwork/pyrex-table-saver
This is an example of the table savers featured in yesterday’s advertisement: http://pyrex.cmog.org/content/celebrating-25-years-service-american-housewives-maker-pyrex-ware-offers-stunning-new-pyrex