In the PERTRA® method the graphomotor skills sandbox supports the writing learning process at the interface between vague coordination and fine coordination. After the child has learned the lines with the help of the road elements, it freely designed the lines out of itself in the sand. In the sand it leaves traces and gives the child a detectible feedback on his actions. Every parameter of dexterity gets addressed, as well it promotes the visual perception. Delivery: with blade and 1 kg of silica sand. 2 rubber rings for closing. In addition, the lid can be used as a framework for 16 insert boards 70x70 mm. LxWxH: 58x16x4 cm.