【SAFE AND USER-FRIENDLY】The ultrasonic insect repellent is a household product that works 24 hours a day, 365 days a year, and does not contain any harmful chemicals that are poisonous, poisonous or emit harmful odors. Ultrasonic frequencies cannot be heard by humans or animals and are completely harmless and safe for pets and children. ultrasound stimulates the auditory nerve with ultrasonic waves in the frequency range of 20 kHz to 65 kHz, destroying the central sense of smell and nervous system of pests and rodents. This ultrasonic repeller effectively repels mice, mosquitoes, spiders, insects, ants, flies, cockroaches, fleas and other pests from your home. 【Large Effective Range】 Each repellent has a range effective up to 1600 square feet. It is recommended to install this ultrasonic repeller vertically 10-32 inches from the floor, and the best results can be achieved by installing an ultrasonic repeller in every room. 【Don’t worry about the activity of the 【Pests】About 3-5 days