It gently stimulates the largest organ in the body... the skin! Its vibrating bristles provide a soothing and relaxing sensory experience. An ideal tool for therapists in clinics or schools for children with autism craving vibration and extra sensory input. Requires 2 AA batteries (not included). 2.5"W x 4"D x 3"H. Use with adult supervision. Features: •Ergonomically correct holder with two vibration speeds (lo and high) •Two interchangeable therapy brushes (one soft and one Wilbarger brush)