This accessory helps you handle the cards easily, and helps keep them in place. It's a 14" neoprene square, 1/8" thick, with rounded corners.
The golden gears show you where to place the 12 cards. When a card is missing, you can really see it, which can be a little harder without the guide. You can also see the Girl Genius damask pattern running behind the gears, as well as some artwork from the game.