I am selling this item because it was effective after one week of use and I no longer need it. Waterproof Anti-Bark Sensor It is resistant to destruction, durable, and weather-resistant, making it safe for use in all indoor and outdoor weather conditions. Equipped with a long-lasting battery, the sonic deterrent functions continuously for 30 days after a full charge of 3 hours. With multiple function modes, you can select from four frequency bands according to the dog breed and size. Size: 12.5 x 9 x 5 cm.