Bluedot Trading 1 mole chaser Solar Powered Ultrasonic Mole Gopher Rodent Chaser Repeller, Set of 1 VERY SAFE:No Poisons, Chemicals, or Traps, that may harm Children or Pets ECONOMICAL: Fully Solar Powered WIDE COVERAGE AREA:650 Square Meters / 7,000 Square Feet DURABLE: Made of ABS plastic and non-corrosive Aluminum TIP FOR USE:Soil density will greatly affect the effectiveness of the device: the more solid the soil, the better the Mole and Gopher Chaser will function.