Repels insects, reptiles, mice and snakes, for gardens, solar powered, waterproof. Emits sound waves every 40 seconds, effective within 650 square meters. Recommend installing 2 devices every 30 meters for rodent areas. Powered by solar cell and rechargeable Ni-Cd accumulator for continuous night operation. Frequency 400Hz-1000Hz. Dig into solid earth to place; avoid frozen, irrigated or waterlogged ground.