ONE 4 DOSE PACK: Amazon Basics Flea, Tick & Mosquito Topical for Extra Large Dogs (over 55 pounds) FAST ACTING FORMULA: Amazon Basics Flea & Tick starts eliminating fleas and ticks within 24 hours of treatment ACTIVE INGREDIENTS: Imidacloprid, Permethrin, Pyriproxyfen address flea infestations by killing flea eggs, flea larvae, mosquitos, biting flies and chewing lice LONG LASTING: One application provides up to 30 days of effectiveness WATERPROOF: 24 hours after application your pet's treatment is resistant against rain and water activities PACKAGING MAY VARY: Packaging may be different than what is shown but item and quality remain the same