Covered with smooth foam for maximum comfort. To help and enhance children's enthusiasm and fun for learning. This corrector can be a good help for bone deformation caused by posture errors, and avoid visual impairment, and can also cultivate good sitting habits. Writing reading posture corrector just clips the bottom shelf onto the desk and adjust the height of the orthotic according to the height of your kids. This product is suitable for desktops of various thicknesses, and can be firmly clamped on the table and is very stable. The height can be adjusted between 9-20cm, suitable for people of different heights.