Sentry Fiproguard Plus for Cats, Squeeze-On Contains the no.1 Vet-Recommended active ingredient, fipronil, and (s)-methoprene, the same active ingredients used in frontline plus Kills fleas, flea eggs, flea larvae, ticks and chewing lice for up to 30 days Stops the flea life cycle and kills flea eggs and larvae for up to 12 weeks Kills ticks that may transmit Lyme disease Product is waterproof