K9 Advantix II is a convenient monthly topical application that kills and repels fleas, ticks and mosquitoes. It's specially formulated for dogs with imidacloprid, permethrin and pyriproxyfen for broad spectrum protection against these ectoparasites that can transmit diseases. K9 Advantix II is for use on dogs 7 weeks and older and weighing 4 lbs. or more.