Advantage for Large Cats offers topical flea prevention and treatment to kill fleas fast and prevent new infestations. The convenient, easy-to-apply, fragrance-free solution works on contact within 12 hours of application to kill adult fleas before they bite or lay new eggs. Simply apply to the back of your cat’s neck, and the treatment works hard for 30 days, treating existing flea infestations and preventing further infestations on cats for up to four (4) weeks. An excellent value from the Advantage brand, Advantage for Large Cats offers relief for your cat at an affordable price. Your cat should be over 9 lbs and at least 8 weeks of age to use Advantage for Large Cats. No prescription needed. Use as directed by label.