CS1 2-Pack Plug In Ultrasonic Pest Repeller (1 pack) How it works: It emits high-frequency ultrasound, causing pests to lose direction and consciousness and drive them away from home. Effectively drives crickets, spiders, mosquitoes, bugs, ants, fleas 100% Child and Pet Safety: Ultrasound is invisible to humans and family pets. It contains no harmful or dangerous chemicals, is a substitute for poisons, and has no unpleasant odor. Easy to use: Simply insert our ultrasonic pest repeller into the socket and let it finish. Unlike glue traps, traps, and poisons, our ultrasonic insect killers do not contain any harmful substances, do no harm, and do not allow you to dispose of dead bodies and pests and rodents. For human and pet safety: Pest repellents do not use dangerous and harmful poisons. The ultrasonic waves it emits only make the mosquito feel unbearable. You only need to insert it. No battery needed! Wide Effective Range: Insect repellent can be used in various places, such as bedrooms, bathrooms, garages, kitchens, offices, warehouses and so on. This is very effective for 1600 square feet. For best results, it is recommended that you install each room. No mosquitoes in the bedroom will affect your sleep