(Bayer) Thanks to powerful attractants and quick killing power, you can transform practically any area in your operation into a fly-free zone. Because flies are lured to the spray, you merely spot spray walls, posts, beams or ceilings where flies tend to rest. Active ingredient imidacloprid even kills flies resistant to current attractants. Kills within one minute and achieves 100% control within four hours. One application provides control for up to six weeks indoors and two weeks outdoors.