Estone Electronic Ultrasonic Anti Mosquito Insect Mouse Pest Repellent Repeller US Plug This machine should be installed at 80-120 centimeter away from the floor. and should be vertical to the floor and plug to the power socket The installing point should be avoided from carpet, curtain etc attaching sound material. or else, the decrease of the sound pressure will do harm on the helminthes effect. It's normal that the mouse and vermin will increase at the beginning of the using days. Because they will get a way from their living place after the attack of the ultrasonic. This machine can be plug directly to AC220V(or 110v)power socket. (Power range:Ac90v-250v.Frequency:50HZ-60HZ Don't clean the machine by strong impregnant, water or damp cloth. Use dry and soft cloth with some neuter wash to clean the machine