... at the warehouse or goods pile-up, one room use one machine is better. Effect Range: ... great effect in 75 square meters in the room This machine can lustrate housefly easily, So ... Can be used outdoor, Better be used in room.The ultrasonic that sent out from this machine ... haberdashery, food shop, furniture store, etc.it applies to villa, house, room used air condition, dining-room, storeroom, etc.Main ...