This is a Revere stainless steel double boiler insert designed for use with the 1940s through 1990s vintage Revere Ware copper-clad saucepans. It's a hard to find, odd size, designed to fit the tall 2-quart and short 1-1/2 quart Revere saucepans (or any pot that is 6-1/8 to 6-1/2" diameter at the rim and at least 3-1/2 inches deep). The insert itself holds one quart (4 cups) to the upper rim. Please note that this size is a little smaller in diameter than the standard 2-quart insert.
The actual measurements of the insert are 6-3/4 diameter rim-to-rim by 2-3/4" deep, 8-1/4 inches wide across the tab handles. The stainless steel finish is in spotlessly clean condition, still shiny with no dents or dings, but there are some hair-fine marks from stirring, cleaning and polishing, mostly to the bottom.