How it works: Tosreny ultrasonic pest repeller emits high frequency ultrasound, causing pests lose direction and consciousness and drive them away. Product specifications: Material: abs Package Contents: 6 pack Standard wall plug in Output power: 2 to 3w Frequency range: 10 khz65khz Effective range: 800 to 1200 square feet Warm tips: Normally, it takes 3 to 4 weeks to see the typical results. It is normal that the increase of insects at the beginning of the using days, as they just get away from their living place after attack of the ultrasonic. so please wait patiently. Use dry and soft cloth to clean, do not clean it with strong impregnation, water or damp cloth. avoided from carpet , curtain and attaching sound material ect.