K9 Advantix II is a convenient, once-a-month topical flea, tick, and mosquito control for dogs. Now containing Pyriproxyfen, Advantix II also kills flea eggs! K9 Advantix II stops biting fleas within three to five minutes and kills 98-100 percent within 12 hours. Repels and kills ticks and mosquitoes. Kills lice and repels biting flies. Remains effective after swimming or bathing. Not for use on cats.