GI.Metal calls this a Universal Disk.

You can use it as a tray to cook the pizza in your oven if you prefer to use a tray rather than a stone.

It can also be used to serve the pizza on, with the holes in the tray allowing moisture to escape, keeping the crust nice and crispy.

You'll notice the top-quality construction on these rigid aluminum disks. They have a rim around the edge providing for a little grip and that leads to the disk being raised off of the table surface slightly.

The diameter on this 12-inches