Simple pounding activities are a great way to develop gross motor skills. This set is made of durable, eco-friendly rubberwood and includes a box, three solid wood coloured balls and a mallet. The balls sit securely in the holes on top of the box until they are pushed through with either the mallet or by hand. The inside of the box is sloped so that the balls will easily roll out the front on their own. The box measures 16 cm x 16 cm x 10 cm (about 6 1/4" x 6 1/4" x 4").