Casio GIEZ Ti-Rubber GS-300 Caliber 2301, ca. 2003
That additional metal shield
is one piece of art. I had no idea that I paid for this rather complex additional shield. It seems over engineered. This "sandwich" serves as the lid of the cage the movement is sitting in. And it serves as some sort of a spring between the movement and the case back. It consists of three layers. An inner metal sheet. A white plastic insulator. And an outer metal ring. You can see some drag marks from the Titanium case back. Those are unavoidable when opening this movement.
Also, don't be surprised if the case back sits very tight. Titanium always creates more friction than stainless steel. I needed quite some force to open the movement today 5 November 2013. Which I had closed previously for the first battery change. If you want to open the watch for the first time, expect a very tight sitting case back courtesy of the factory robot!