Corning Vision 1.5 Liter amber double boiler insert with cover. According to the LeClair.Vision website, these were available from 1984 to 1993 and were made in France.
This insert is in good condition with light wear, especially on the bottom, and no cracks. There is a small chip on one of the handles that I have photographed. The cover is in very good condition with light wear and no chips or cracks. It would make a great addition to your Vision 1.5 Liter pot!