The Bayer Seresto Flea & Tick Collar for Large Dogs over 18 pounds provides continuous 8-month flea and tick protection. Unlike oral flea and tick prevention products that require a bite, the Seresto collar repels fleas and ticks and kills through contact; no biting required. Frontline flea and tick treatment does not repel (based on label claims). Seresto dog collars are made with a long-lasting, 8-month formula for continuous release coverage over your dog's skin and coat, and are water-resistant and remain effective after shampooing, swimming or exposure to rain or sunlight. (Dogs must not be bathed more than once per month. For dogs that swim once a month or more, the control duration is reduced to five months for flea control, and reduced to seven months for tick control.) This odorless, non-greasy collar is easy to apply and can be used alongside other identification or restraining collars without damaging them. Avoid the hassle of messy monthly treatments and get the effective protection of Seresto. Features: Provides 8 months of continuous flea and tick prevention Works through contact, killing and repelling fleas and ticks, so they don't have to bite your dog to die Active ingredients imidacloprid and flumethrin are slowly and continuously released in low concentrations, spreading from head to toes, even the tail, over your dog's coat and skin Also aids in the treatment and control of sarcoptic mange and kills lice Vet-recommended flea and tick protection for dogs in a convenient, odorless, non-greasy collar; no need for messy monthly treatments Intended For: Dogs and puppies 7 weeks of age and older Leash Type: Flea & Tick Collar Pet Weight: Small: Dogs up to 18 lbLarge: Dogs over 18 lb Caution: It is a violation of Federal Law to use this product in a manner inconsistent with its labeling. Do not contaminate feed or food. Available Sizes: SmallLarge Seresto Flea and Tick Dog Collar Size: Large