This all-in-one pack provides great sensory feedback to any child. It comes with four colorful nubby balls in a variety of colors. The mega pack includes two 7-inch balls and two 4-inch balls in see-through and opaque colors. The bright colors will captivate your child visually, while the nubs provide great feedback to their upper extremities (fingers, hands, arms). The nubby texture provides a massage-like sensation. Try rolling the ball on their legs, arms, back and belly to awaken their senses. My son loves to hug these as it will stimulate a larger area of his body all at once. You can use the sensory balls for gross motor skills as well by practicing throwing, kicking and catching the balls.