6 Month Supply Cats 6 lbs and over Sentry PurrScriptions PLUS Cat and Kitten Squeeze-On Flea and Tick Control. Over 12 weeks or older Provides 5 way protection from fleas, deer ticks, flea eggs, larvae and mosquitoes. Effective for up to one month. For cats and kittens that weigh over 5 lbs. Kills flea egg and larvae for up to three months. Quick drying formula.