Say hello to flea and tick control you can count on! With the PetArmor Extend Collar for Large Dogs (above 18 lbs.), you can protect your dog for up to eight continuous months, without a prescription. This scientifically proven collar kills and repels fleas, ticks, and lice through contact, so they don't even have to bite your dog to die. It starts working 24 hours after the initial application. New fleas are killed within two hours, while protection against new ticks starts at 48 hours. It also targets flea larvae, helping to break the flea life cycle and prevent them from coming back. Made with the #1 vet-recommended active ingredients, the Extend Collar delivers effective protection that keeps working even if your dog gets wet. The active ingredients, imidacloprid and flumethrin, are slowly released from the collar and spread into your pet's skin and coat, delivering long-lasting, water-resistant protection. This formula is completely odorless and non-greasy, leaving no chemical smell or residue behind. With season-to-season coverage, you can have peace of mind knowing your dog is shielded with the hardest working collar that money can buy. Join the millions of pet parents who already protect their pets with PetArmor!