NO HAZARD TO HUMANS AND PETS:No noise, non-toxic, no harmful chemical gases will be produced. 100% safe and odorless for humans, children and pets, perfect for getting rid of all types of rodents and insects including mice, rats, spiders, mosquitoes, bugs and ants . LIGHTWEIGHT DESIGN:The ultrasonic repeller is portable and easy to install, just plug and play. Widely used in home, warehouse, office, garden, hotel, etc. Energy saving, protect you from pest intrusion all day long without worrying about your bill. Instruction:Simply plug the pest repeller into a wall outlet (at least 80cm to 120cm from the floor ) emitting powerful ultrasonic waves that deter a range of insects and rodents - instantly the room will be protected. LARGE COVERAGE AREA:The ultrasonic repellent is effective for an area of up to 800 at 1,200 square feet. Please note that ultrasonic waves cannot pass through walls. It is best to use at least 1 unit for each room and use at least a few units for areas with