Instructions:1. This repeller should be installed 10-30 inches above the floor.2. For best results, do not plug in behind furniture or curtains.3. It can take from 3-4 weeks for insects and rodents to leave your home or apartment. For the first two weeks, you may notice activity increase as they move from their den, hive, etc.4. Keep away from hamster pet.Ultrasonic pest repellers offer a safe, non-toxic was to manage insects and rodents. The high frequency sound emission is not noticeable by humans and pets. The sounds annoys insects and rodents creating a stressful environment for them.Package Includes:2 X Ultrasonic Pest Repellents