SENTRY PurrScriptions Plus Squeeze-on is formulated with an adulticide called Etofenprox. When applied monthly, Purrscriptions Plus kills adult fleas, deer ticks, and repels mosquitoes, including the mosquito that carries West Nile virus, for up to one month. This product also includes pyriproxyfen, an insect growth regulator that kills flea eggs and larvae for up to three months per application. That's five-way protection! Kills adult fleas and deer ticks, as well as repels mosquitoes for up to one month. Insect growth regulator kills flea eggs and larvae for up to three months per application. For cats and kittens 5 lbs. and over, over 12 weeks of age. qContains 3 application tubes