Is this a Confectionery Ganache frame?
To me, this looks like a tart ring. In commercial kitchens, tarts are not baked in pans, they are baked in ring walls arranged on baking sheets. 

The traditional rings are round (duh), but the word has stayed for the square and rectangular versions. And of course, it can be reused for purposes other than baking tarts, since the shape is convenient for many tasks. 

So, look for purchasing a "rectangular tart ring" and you'll likely find what you need.