The Crunchy Caterpillar has larger stainless steel beads WITH A DIFFERENCE! They have texture and create a sound and 'crunchy feel' on roll. It’s a bit similar to rolling the flint of a lighter in sound and sensory input. Many rub the cord also. You can push your fingers in between the beads for a similar sensation to the pea popper.
Not suitable for 3 and under as beads can pose a choking risk.