Easy Installation - Simply plug it in to household power socket vertically. This machine should be installed 80-120 cm from the floor. The LED light will illuminate, which indicates the device is working. One pest repeller can protect 80-120sqm. To enhance the performance, please use more than one device in large rooms. Noiseless and Odorless - The ultrasonic waves that this repeller sends are far beyond the hearing range of human-beings. Enjoy a peaceful & pest-free tight sleep without any concerns for noise. Safe & Eco-friendly - The electronic pest repellent is designed for environmental protection and 100% safe for human. No radiation, no chemicals, non-toxic, no smell and no noise. Just drive pests without killing them, an environment-friendly and humane solution to keep the pests from your home. Wide Applications - The pest repellent can be widely used in home, warehouse, shop, hotel, hospital, office, grain depot, etc. Please be aware that this repeller is for indoor use only. Ultrasonic Technology - Ultrasonic can act upon the hearing and the nervous system of them to make them unpleasant and uncomfortable, which drives them from your home. Outdoor insects and rodents won 't enter your home. Eliminates Mosquitoes, Mice, Spiders, Ants, Flies, Roaches, Bugs, Fleas, Rats, etc. Plug Type:US Plug,it applies to Canada, India,Mexico, Thailand, the United States, the Philippines,Taiwan and so on. Condition: 100% New Power Supply: AC 90V-250V, 50-60Hz Power: 5-6W Ultrasonic Frequency: 22-65KHz Effective Range: 262-393 Square Feet Working Temperature: 0-40Celsius colour:White+black Material:ABS size:8.7 x 5.6 x 3cm Package Contents: 4 x Ultrasonic Pest-Rodent Repeller Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.