The Touch Boards set (also called the Rough & Smooth Boards) consists of three wooden rectangular boards with a series of rough and smooth surfaces for developing the tactile senses and the ability to identify different grades of roughness. On one board, half of the surface has a smooth piece of grey fabric while the other half is rough with medium grit sandpaper; the second board has a series of alternating medium grit sandpaper strips and smooth fabric strips; the third board has a series of rough sandpaper strips arranged in gradation from almost smooth to very coarse. Each board measures 24 cm x 14 cm (about 9.5" x 5.5"), and the whole set comes in a wooden storage box with a lid.