Some TipsPlease using low-frequency mode when you're in the room. The low-frequency mode has no noise or has a little noise but people can't hear. If you want to get better effect, you can use high-frequency mode when you are out of home. It's more powerful when using the high -frequency mode but people can hear it. Innovative Frequency Conversion TechnologyThis indoor complement emits invisible electromagnetic waves to expel insects, mice, rats, mosquitoes, ants, spiders, cockroaches, and other insects. Without having to kill them. Please note that our ultrasonic repellents work between 2 and 4 weeks to make an effect depending on the amount of infestation. Then we can say goodbye to pests and mice. Plug and Play & Full CoverageUltrasonic Pest Repeller can be used in various places, such as Bedrooms, Bathrooms, Garages, Kitchens, Offices, Warehouses, etc.The Adopt Imitation sound wave technology & latest ultrasonic Pest Repellent is effective for an area up to 1300- 1650 Sq.NotePlease make sure to install it vertically 7-31inches away from the floor. And make sure there are no barriers like curtains or cabinets covering in front of the repellent. Safe & Environment-Friendly: Without poison, chemicals, traps and killing, the Pest Repeller is safe and harmless to humans, children and pets. It is a physical method to drive pests away, non-toxic, eco - friendly, and absolutely safe for children and pets, a pest repellent combining advanced technology and humanitarian.But if you keep hamster as a pet in your home, please do not use. Color: 1: black, 2: gray Weight: 75g Product specifications: 1: U.S. standard, 2: European standard, 3: British standard Size: external dimensions: 9.2 * 7.3 * 6.3 cm Rated power: 4-6W Power frequency: 50-60HZ Effective range: 110-150 meters Power supply voltage: AC90-250V Package includes: 1pc * mosquito repellent