Check the listing for details. NPS Alpha Dog Behavior Trainer Anti Bark-Barking Control (Free Shipping). Condition: New. Listed at 17.99 USD. Train your canine companion effectively with the NPS Alpha Dog Behavior Trainer, an anti-barking device designed to help you establish order and calmness in your pet's behavior. Suitable for dogs ranging from 6 months to 8 years, this device emits a high-pitched sonic whistle that's inaudible to humans but interrupts your dog's barking with its loud sound, up to a range of 35 feet. The trainer comes with a rechargeable battery, ensuring that you can rely on it for consistent use. Its durable design, featuring impact resistance up to 35 feet, guarantees that it can withstand the rough and tumble of daily training sessions. The model, Alpha, is a must-have for any dog owner looking to maintain a harmonious living environment.