This product is designed like an alarm clock. The luxury ultrasonic outdoor bark deterrent can be hung on a tree, placed anywhere in the house, or in the yard. It can be hung, placed on a table, or in other locations. When the bark deterrent detects excessive barking, the microphone picks up the sound and activates the device. It then emits a safe, high-frequency ultrasonic sound that dogs can hear but humans cannot. The sound stimulates the dog, causing it to stop barking. Excessive barking can affect you and your neighbors. This ultrasonic outdoor bark deterrent effectively stops dogs from barking without a receiver collar. Safe and effective, suitable for all breeds and sizes. K6 Digital Ultrasonic Outdoor Bark Deterrent with Digital Display and Rechargeable battery. Four frequency settings: Choose according to different pets, animal types, or sizes. Seven sensitivity levels: 1-4 levels with digital display, where level 4 is the most sensitive. The display shows the current status. UV-resistant housing: The product does not fade easily under the influence of UV radiation from the sun. IP4 waterproof. Specifications: Weight: 0.2 kg / set. Dimensions: 12.5 cm × 9 cm × 5 cm.