From the Manufacturer:
The Pro-cision Flo® applicator (patent pending) easily penetrates the fur for improved application directly to your cat's skin. Hartz® UltraGuard Pro® Flea & Tick Drops for Cats is a monthly treatment that kills fleas, deer ticks and mosquitoes plus kills flea eggs and larvae to prevent future infestations for up to 30 days, stopping the flea life cycle. Do not use on kittens less than 12 weeks old. Package contains 3 monthly treatments.