Sentry PurrScriptions Plus squeeze on contains the adulticide etofenprox and the insect growth regulator pyriproxyfen. One monthly application kills adult fleas, ticks and repels mosquitoes, including the carrier of West Nile virus, for 30 days. Pyriproxyfen further controls flea eggs and larvae for up to 3 months. Each package includes 3 application tubes for cats and kittens over 12 weeks and under 5 lbs.