This is the Volcano Board that comes in Pyramid Arcade. It's solid white molded plastic, 6.75" across, nice and sturdy. Holds 25 pyramids upright in a 5x5 grid. ELBS do fit into this board if you want to block off some portions.
The molded plastic feels way more solid than I expected for something this size, and pyramids sit snug in the 5x5 grid without wobbling. I've been using it for solo puzzles on the coffee table and it's held up great.
Wasn't sure the 5x5 grid would hold the pyramids snug, but they sit upright with no wobble at all. The board is 6.75 inches across and thick enough that it doesn't slide around on the table. Nice bonus that the ELBS fit in too.
The molded plastic feels far more substantial than the price suggests, and setting up a full 5x5 grid of pyramids takes seconds without any wobble. I've been using it as the centerpiece for quick solo games, and it's held up perfectly to daily handling.