PETARMOR 2 Count Flea & Tick Collar for Dogs Each PetArmor Flea & Tick Collar for Large Dogs kills fleas and ticks for 6 months when worn continuously This vet-quality flea and tick collar is safe for pups 12 weeks old and up, and fits dogs with necks up to 22 inches A PetArmor flea collar kills adult fleas before they can lay eggs, helping to prevent reinfestation Flea and tick treatment includes 2 waterproof collars for a whole year of all-weather, whole-body protection Flea and tick prevention for dogs protects your furry family member from ticks that may transmit Lyme disease