Sensory balls AM Tullo 3pcs 453 The balls will work for whole body massage, exercise muscles hands and sensory therapy. Stimulate sensory receptors, sense vision Improves ability grip. Durable. Needed during crawling for rolling by baby. During teething for massaging gums. For massage. Approved materials . They are safe because they don't contain phthalate, BPA, heavy metals. 3 balls.