9 inch Diameter Knobby Ball. Ideal for sensory and dexterity development. This ball is mainly for outdoor use. Fun, nubby surface is great for tactile development as well. Wipe off dirt and mud easily with warm water and a paper towel. Deflates for easy storage. Visually stimulating with bright vibrant colours. Refines fine and gross motor skills Promotes tactile exploration Babies love to explore!