Solar Powered: Powered by a rechargeable solar battery. 4 hours of charging the ultrasonic solar repellent in sunlight will be enough to keep them working for 4 days. The mole repellent stakes emit 3-4 seconds of low-frequency pulses every 20 seconds. Note: Keep the solar pest repellent stakes under the sun to charge for at least 2 days before installation. Safe for children and pets: No chemicals or poisons are used in this process. The mole repellent stakes emit 3-4 seconds of low-frequency pulses every 20 seconds. They penetrate through the ground and discourage them from entering the protected area. The humanized way to repel moles, the repeller protects the roots of lawns, vegetable fields, flowers and seedlings. Prevents moles from digging tunnels. Wide Coverage: Each mole repellent has an effective range of up to 2,200 feet. It is recommended to install the mole repellents every 70 feet in your lawn for optimal performance. 8 Pack mole repellents for an excellent environment.