The PetSafe Ricochet is an automatic dog toy that will provide your dog with a fun and exciting activity. With sounds that move between the balls as the dog plays.This provides your dog with low level play and mental stimulation. Each "ball" is powered by three AAA batteries, after 60 minutes of no activity it will turn off to save battery power. This means that one charge of batteries lasts for approximately one month of daily play. Facts about PetSafe Ricochet Electronic:Provides your dog with metal stimulation.With sounds that move between balls during play.Powered by 3 AAA batteries each.One pack contains two "balls".