Effective Wide Coverage Solar-Powered Mole, Vole, Gopher Groundhog, Chipmunk Repellent Solar Powered Package Includes: 8 x Ultra Sonic Mole Repellent Stakes 1 x User Manual Specifications: Solar Panel Size: 65 x 65mm （2.55 inches） Newly Designed Panel Shape: Octagon Effective Range: Approximately 7500 sq. ft. Material: ABS Plastic Working Way: Buzzer Cycle Interval: Appr 20 Seconds NOTE: ◾ For the first installation, the mole repellent requires up to 2 days of the sunlight to be fully effective. ◾ Insert the stake into ground,make sure the top is above to the surface by roughly 2 inches. ◾ To ensure the best effect, place one solar mole repeller every 70 feet in the aimed areas. ◾ Position the device where it gets full sun on the panel to charge the unit. ◾ The mole repellents need to be used continuously for 7-14 days before ground rodents start to move away from the area. ◾ The harder/denser the soil, the better it works, as the sonic vibrations do not travel well through loamy soil conditions.