Results. Well these flash guards are very effective on mosquitoes and for the long time. Suppose you light them at 9 night hours of the night and then you can only expect it to be effective for two to three hours only I might be wrong after this you again have to light another card if you want to sleep comfortably in the bed. Without worrying about the mosquitoes. And user friendly Ness can be is bit low they are not provided in proper casing you have to wash your hands after touching them.