Perfect Dog Command Collar helps correct problem behaviors like jumping, barking, pulling, digging, stealing food and destructive chewing. With Don Sullivan's Perfect Dog Command Collar® device and training DVD, you can correct problems behaviors and transform your relationship with your dog within minutes! Don's easy-to-follow approach gives anyone the tools that took Don decades to develop. Designed to achieve success where all other methods have failed. The command Collar action emulates a mother dog’s natural corrective process. It gets your dog’s attention and helps your dog respect you as his leader. The natural way to change your dog’s behavior. The Perfect Dog Command Collar gets results in minutes! Includes collar and 30 Minutes to the Perfect Dog DVD. Adjustable from7-24 inches suitable for large dogs.