Ultrasonic Mouse - This is our premium version. Using the principle of ultrasound, the frequency is changed to stimulate the auditory system of mice and other pests, making them intolerable and uncomfortable. Number of pieces: 3 pieces Wide Coverage - The ultrasonic mouse is suitable for large areas up to 800-1300 square feet. Note that ultrasound cannot pass through walls. Although our ultrasonic repellents work well, if you have a large infestation, we recommend that you place our repellents in each room. EASY TO USE - The unit should be installed 80-120cm from the floor. And perpendicular to the floor and plugged into a power outlet. Can be directly inserted into an AC 110V power socket (power range: AC 90V-250V frequency: 50-60HZ). Fluently used in homes, warehouses, stores, hotels, hospitals, offices, etc. Large areas may require more than one unit. ECO SAFE - The product is non-toxic and environmentally friendly, our mosquito repellent is 100% safe and effective, and the