Check out this review of the Babybjorn Bouncer Balance Soft! http://www.babybjorn.com/baby-bouncers/baby-bouncer-balance-soft/ From BabyBjorn.com: The Bouncer Balance Soft runs on fun alone – no batteries required! Your child’s own movements will bounce the chair. Your child can have fun bouncing, while developing motor skills and balance in a completely natural way. Younger babies can be gently calmed by carefully bouncing the chair with your hands or feet. Ergonomic bouncer