Sweeney's S7915 Solar Sonic Spike PRO Repellents with Hyper Pulse Technology Moles, gophers and other burrowing animals are chased away unharmed Solar powered, rechargeable batteries included Sonic pulses and vibration emitted every 30 seconds Each spike covers up to 13,500 sq. Feet (1/3 acre) Operates in a circular pattern, approximately 130 ft. In diameter