Four Function Switch: TEST = test tone (simulate the sound heard by rodents, check whether the device can work). ULTRA = Ultrasound (effectively repel mice and rodents). TRANS = pressure wave (effectively repel squirrels). DUO = pressure wave + ultrasound (rejects all pests, rodents and insects) Provides More Coverage: 360° ultrasonic release to effectively repel rats, mice, squirrels, cockroaches, spiders, fleas,ants and other rodents and pests. This Ultrasonic pest repellents can be used effectively in indoor areas up to 1076 square feet. This has a significant effect on expelling rodents from homes, warehouses, offices, gardens, hotels and other indoor areas. Maximum Effectiveness: The pest repellent ultrasonic plug in emits powerful ultrasonic sounds and pulse wave that disrupt rodents' brain system; Built-in LED flashing lights disturb their activity in a dark environment, being extremely irritating to rodents and pests; This ultrasonic pest repeller makes the area uncomfortable for rodents and bats to be in, then they will run away from your house Humane and Safe: Non-toxic, radiation, harmful checmicals, Odorless, Inaudible and 100% Safe to human and pets. With CE and ROHS certifications, our products can repel rodents and pests effectively without harming humans and pets. Long-lasting Protection for Property: Place the pest repeller rat repellent in the Attic, Garage, Basement, Room, Storage, RV, or any indoors 100-240v available; Save your money for rodent control, and prevent your property in mice damage, repelling squirrels, mice, rats, and bats from your home Note: Products with electrical plugs are designed for use in the US. Outlets and voltage differ internationally and this product may require an adapter or converter for use in your destination. Please check compatibility before purchasing.