This ultrasonic pest repeller is made of ABS material. It uses ultrasonic frequency (22 to 65 kilohertz) sound waves to drive pest away instead of killing them. Safe for human and pets like dogs and cats. Odorless, noiseless and no radiation, safe for pregnant woman and baby. Usually, it takes 2 to 3 weeks to make effect. It can help drive away all the pests, like spiders, mices, mosquitoes,roaches, insects, bugs and so on.