More efficient with automatic frequency change - Stronger ultrasonic wave will automatically and constantly change from 20~60KHz every 30 seconds, making pests and rodents harder to immunize than before. Expel insects, rats, mosquitoes, spiders away from home. Easy to use with AI Chip Plug n Play - Easy to use. Plug in and use. The AI chip enables the ultrasonic pest repeller to emit respiratory ultrasonic waves, no need to change the frequency manually, just plug it into the socket and turn it on. Safe and child and pet friendly - Pest repellent is odorless, quiet and radiation free. no dead pests. Its ultrasonic sound makes pests unpleasant and uncomfortable, which is inaudible to humans and pets. 100% safe for pregnant women, babies and pets. Surge Protection and Power Saving - Over 30000 hours of comprehensive testing, durable to last a long time. new flame retardant ABS-A1 plastic, safe to use. Quick solutions within hours if you have any questions about ultrasonic pest repeller.