The LEA 3-D Puzzle is designed for supporting the development of the concept of "same", first with colors, then with black & white concrete forms that are prerequisites for the measurement of recognition acuity with the LEA SYMBOLS® tests at an early age. During the play you can also observe eye-hand coordination and awareness of directions, which are often problems for children with brain damage, even mild brain damage. Package includes the booklet: Assessing Vision Development Through Picture and Shapes and instructions. Tray is 6.75" x 6.75" (17.2 cm x 17.2 cm). The 4 symbol puzzle pieces are approximately 2" x 2" (5.1 cm x 5.1 cm) each.