The effectiveness ofall ultrasonic anti-bark devices lies in the intensity of ultrasonic waves and the transmission range. This product has 2 ultrasonic speakers, which increases the intensity of ultrasonic waves by 100%, and the range of ultrasonic waves is also significantly improved. The Teptec dog barking control device comes equipped with two ultrasonic speakers. The device can reach a distance of up to 55 feet! You can expect great results at this distance stopping excessive barking from your neighbor's or your dog . This product uses a 1500mAh rechargeable battery, which can be used continuously for 15 days after charging for 5 hours.Using the old version of the dry cell will cost you an extra five 9V batteries, worth 20 dollars per month. It has three gears that can adjust the frequency, which is effective for almost all types of dogs. One to three gears are suitable for large, medium, and small dogs, respectively. It is only about the size of a palm, with a length, width, and height of 3.5*3.1*4.3 inch, which does not take up space. The owl-shaped form also allows it to blend in with both indoor and outdoor environments. The IPX4 waterproof ability makes it resistant to liquid splashing in any direction, making you less worried when choosing the layout environment, and also dramatically increases the durability of outdoor use. The product has a sturdy base; you can place it directly on the furniture surface or the ground; or hang it from the wall or tree with the included short cord. Must be within 55ft, best within 15ft.The speaker should be directed toward the dog. Level1(20KHz): Suitable for large dogs.Level2(25KHz): Suitable for medium dogs .Level3(30KHz): Suitable for small dogs. It will automatically recognize and send out ultrasonic waves to stop barking.Combined with training to achieve better results. Next page Dual Ultrasonic Speakers 55ft Effective Range Rechargeable, More Economical 3 Adjustable Gears Suitable for Indoor and Outdoor: Compact Size IPX4 Waterproof Suitable for Hanging or Placing Simple and Easy to Use: 1. Choose a Placement Location 2. One-button Start 3. Automatic Stop Barking Videos for this productCustomer Review: Keeps my dog quietVideos for this productCustomer Review: Small but effectiveVideos for this productThe BEST Dog Barking SilencerVideos for this productCustomer Review: Beeps while chargingVideos for this productCustomer Review: We have our yard back!