The PetSafe deluxe outdoor bark control.

The PetSafe Deluxe Outdoor Bark Control (Model PBC17-13475) is an outdoor, birdhouse-disguised ultrasonic device designed to deter nuisance dog barking from up to 50 feet away. It features an internal microphone that detects barks and triggers a high-pitched ultrasonic tone that is inaudible to most humans but grabs a dog's attention. The weatherproof unit also includes programmable digital timers to manage battery life and prevent dogs from getting desensitized to the sound.