This block press, or seam press, is made from a thick piece of transparent acrylic plexiglass, as well as an unfinished wooden handle. It allows a quilter to "lock" a completed block in place after pressing it. The transparent nature of the acrylic base allows quilters to see which block is under the press, without lifting it (or trying to remember).
The acrylic block press comes in 3 sizes: 8x8, 10x10, and 12x12.