Designed to assist you with obedience training and behavior modification of your dog or cat by taking advantage of the sensitive hearing. The ultrsonic frequency is inaudible to most humans. The negative tone button activates the ultrasound which startles your pet more than yelling or a firm voice command. There is also a positive tone for rewarding good behavior. The transmitter has a 30-foot range and uses a 9-volt alkaline battery (not included). Manual included. Non-returnable 3 days after receipt.