Feature: Ultrasonic Electronic Anti Mosquito Pest Mouse Insect Cockroach Repeller Reject Have effect in 80-120 square meters in the room. Can lustrate house mouse, black beetle, mosquito etc. Do not harm to human being and pets. Not have affect on house machine. No-toxic, safety and environment protected. Low energy consumption. Specifications: Color: White Input:110-220V, 50-60Hz Input power:5W Output audio:22-65 KHz Using environment temperature: 0-40C Size: 90 x 56 x 28 mm Notes: 1. This machine should be installed at 80-120 centimeter away from the floor, and vertical to the floor and plug to the power socket. 2. The installing point should be avoided from carpet, curtain etc attaching sound material. Otherwise, the decrease of the sound pressure will do harm on the effect. 3. Its normal that the mouse and vermin will increase at the beginning of the using days. Because they are moving away from their living place after the attack of ultrasonic. 4. To increase the effect, you should use several sets of this machine at the warehouse or goods pile-up, for the best using range is 50 meters. 5. It can't drive ants away 15Pcs Electronic Ultrasonic Pest Reject Mosquito Cockroach Mouse Killer Repeller The ultrasonic frequency emitted from this machine is not audible to humans and pets. It's absolutely safe for children, families and pets. For 100 to 150 square meters of the area is effective. This product is widely used in homes, warehouses, shops, hotels, hospitals, offices, rooms, gardens, hotels and so on. The ultrasonic rejection device can disturb the hearing and nervous system of mice, rats and insects, making them unpleasant and uncomfortable and forcing them to leave your home.