General description A humane and safe way to repel moles, gophers, groundhogs, voles, and other burrowing rodents, these solar-powered ultrasonic repellents chase away pests unharmed. They operate without chemicals, making them an eco-friendly solution for your garden. Technical specifications Solar-powered with a 4-hour solar charge lasting up to 5 days Coverage area: approximately 40 ft. in diameter Pulses emitted every 3 seconds for 30 seconds Material: plastic Color: green Measurement allowed error: +/- 1-3 cm Compatibility and accessories Package Contents: 8 x Solar Powered rodent repellent Usage It is recommended to use 12 solar mole repeller units per acre for optimal effectiveness. Generally, it takes about 2-4 weeks to drive moles and other pests away from your garden.