Features: Ultrasonic pest repeller can effectively repel mice, mosquitoes, ants, spiders, etc. Non-toxic and harmless to humans and pets, an alternative to toxic chemicals and traps. Wide frequency range(20KHz-85KHz) and variable frequency during working. Protects an area up to 120-180 square meters if there is an open space. Just plug in the socket, so easy and convenient to use. With LED indicator and the night light is great for night use. Low power consumption, suitable for long time operation. Notice: 1. Installation height: 30cm from the floor, and vertical to the floor. 2. Avoid mounting the device in the back of the curtain, fridge, and any other furniture that deterring or attaching frequency. 3. It's normal that pests will increase at the beginning of the using days because they are moving away from their living place after the attack of ultrasonic. 4. Don't clean the machine by strong impregnant, water or damp cloth; use dry and soft cloth with some neuter wash to clean it. 5. To increase the effect, you should use several sets machines at the warehouse or goods pile-up, several rooms.