Kinven flea & tick collar offers a breakthrough of 4 Months protections for dogs or cats, setting it apart from conventional flea and tick collars It offers performance of topical with the non-greasy convince of easy to use collar. Its sustained release technology means that the active ingredients are slowly and continuously released over 4 month. Kills and continues to prevent re-infestations for up to 4 month Product Details . Sustained release technology provides 4 month flea and tick protection . Veterinarian recommended collar repels and kills fleas and ticks . Provides non greasy, odorless flea and tick prevention insecticide . Preventive mediation that repels ticks and stops transmission of disease-causing organism . Top rated flea and tick collar eliminated pesky pests . Water resistant when dog is bathed or swims once monthly and remains effective following monthly bathing .Size adjustable Comes in 3 Sizes Large -23.5 inches for large dogs Medium – 16 inches for small dog Small – 12 inches for Cat