Features: Built-in smart chip can continuously change frequency and emit a powerful range of ultrasonic sound waves that can effectively drive mice away. The frequency is within the range of 22~45（KHz）which is safe to humans and pets, but would cause damage to mice nervous system. Constructed with damp-proof material, it is silent in operation, ensuring a sound sleep in quiet environment. Can be used as a aroma diffuser, serving multiple purposes and bringing a pleasant living environment. Effective coverage up to 80 square meters, keeping pests away, can be used in bedroom, kitchen, warehouse, office and stores.