Bayer Advantage II is a fast-acting, topical flea treatment for dogs that kills fleas within 12 hours and prevents fleas from re-infesting. It contains a new and enhanced formula with a flea control solution that targets a flea's complete life cycle to kill eggs and larvae and inhibit development. Advantage II uses adulticides and insect growth regulators (IGR), such as imidacloprid and pyriproxyfen, to kill fleas on contact and lessen flea allergies. Product is waterproof. Includes 4 monthly, easy-squeeze tube applications. Use only on dogs 7 weeks and older. For small dogs up to 10 lbs.