2 pack Most effective & powerful: the mosquito zapper made of high quality material. It operates noiselessly by simply plugging it into an AC outlet. It attracts bugs with emitting high-intensity UV light. Then the electrically charged high voltage metal grids will electrocute the insects. You will get rid of all unwanted insects and bugs immediately. Note: This bug zapper can be used for indoors only. It should be positioned in room darkest areas, far from windows or other light sources. Due to electric shock danger, please keep it away from the children is necessary.