Creates an underground vibration so intolerable to moles that they quickly vacate your yard. This is an easy and humane alternative to poisons, gasses and traps. Rust proof steel contruction. Uses wind driven 18 in. windmill-like blades to create vibration, and only a soft wind is needed to keep the blade spinning. Easy to assemble. Just attach the Mole Chaser to the top of several feet of 1/2 in. rigid pipe (not included) and mount the pipe in the ground.