PetSafe Indoor Bark Control Ultrasonic Pet Training System FOR DOGS OF ANY SIZE  uses high-frequency sound that works to reduce excessive bark of dogs within hearing range; for dogs 6 months and older UP TO 25 FOOT RANGE VERSATILE - you can use either freestanding or hand-held. Microphone detects barking to prevent false corrections TWO SETTINGS - you can set the unit to automatically emit the ultrasonic tone when your dog barks or press the manual button to correct inappropriate behavior NO BARK GUARANTEE - Some dogs may not be responsive to ultrasonic correction. If this product is not meeting your needs, please contact PetSafe Brand AVERAGE BATTERY LIFE 5-6 months - takes a 9-volt battery (not included) and will last up to 6 months depending on use Call, chat or email with our expert PetSafe US-based customer care specialists six days a week; They are waiting to assist you and your pet with your product needs at 1-800-732-2677 or by email at ccc3@petsafe.net Manufacturers warranty is only valid when purchased from an authorized retailer