Effective: Once the animals enter the protection range, the PIR sensor will start to work, then it will emit ultrasonic waves and the red light will be on so that it will repel the animal. < p> Solar Powered & Waterproof Design: This ultrasonic cat repellent can be powered by solar power under the sun, which is economical and environmentally friendly. Larger detection area: The PIR infrared motion detector has an angle of up to 50 degrees and a detection range of up to 8 meters. Large detection area up to 230 square meters. Get rid of pet droppings, food destruction, noise and footprints in just 1-2 weeks. Easy to install and use: you can simply push the animal repeller into the ground, or hang it on the wall through the back slot (with direct sunlight recommended) Tip: if you turn on the repeller to chat when you receive it, there is no response. Please charge it under sunshine for about 2 hours and it will work.