PetSafe Deluxe Outdoor Ultrasonic Bark Control - Elite No Barking Deterrent for All Dog Sizes - Up to 1/4 Acre (50 ft) Coverage - Weatherproof - Timer for Scheduled Activation - Bird House Design

Outdoor Bark Control: Disguised as a birdhouse, the unit emits an ultrasonic tone when your dog barks that can be annoying to your dog but is silent to most humans | Small Outdoor Spaces: Each weatherproof unit covers 1/4 acre; add more units to cover a larger size space; hang them in a tree or place on a solid surface outside | Gentle Bark Control: The high-frequency tone (which humans cant hear) works on all size dogs 6 months and older | Built-In Digital Alarm: The timer works like an alarm clock; turn the unit on and off at specific times to help your pup from becoming desensitized to the ultrasonic tone | Low Battery Indicator: Each unit uses a replaceable 9-volt alkaline battery (not included) and has an LED low-battery indicator | U.S.-Based Customer Care: Our pet product experts are here to help you and your pet and are available by phone, email or chat if you have any questions | Quality Promise: PetSafe brand has been a trusted global leader in pet behavior, containment and lifestyle innovations since 1998 to help keep your pet healthy, safe and happy