Made of extra-tough rubber, interlaced to form a heavy-duty ball. The result is a chewable toy that rolls and bounces. Nobbly Wobbly II Balls are made of extra-tough rubber, interlaced to form heavy rubber balls. The result is a groovy shape that bumbles, bounces, and rolls. The bright rainbow of colors in each ball will entice your dogs, and the one-of-a-kind feel will encourage them to love these funky toys. Small 3 In.