Solar Ultrasonic Animal Pest Repeller with PIR Sensor for Farm, Yard, Garden,Backyard Different frequency setting: 13.5kHz-17.5kHz for repelling small pest like rats,etc;15.5kHz-19.5kHz for repelling dogs,fox,etc;19.5kHz-23.5kHz for repelling little dogs,cats,brids,etc. Unique design and high quality, made of waterproof material, durable in use. Use solar energy eco friendly, Chemical free, safe to human. Working time no less than 8 hours when full charged. Easy installation, just insert the bar into the earth.