Untrasonic Mosquitoes Repellent 1.No poisons,no traps,no dead pest cleanup 2.good function 3.long life time 4.protect house RC-505A Principles: Making use of Ultrasonic principle,disturbing mouse's brain nerves,which causing the mouse's Central Nervous and Hear System have strong reaction.Then they can't bear and run away.The using range:Home,restaurants,supermarkets,farm,storeroom,kindergarten, ...