4 each of our 3 Best-Selling "Basically Impossible" Puzzles, including our Rainbow, Earth and Candy Pentomino Puzzles. These colorful puzzles are sure to keep puzzle lovers occupied for hours. Arrange the twelve different pieces by rotating and flipping them in order to get them all to fit inside the boundaries of the frame. These pentomino puzzles are our most challenging puzzle and have been described as basically impossible. Each comes packaged in a clear sleeve. 5" x 5" x 0.25". Materials: acrylic, baltic birch.