Kills 98-100% of the fleas on cats & dogs within 12 hours. Prevents further flea infestation for up to 4 wks on cats. Kills fleas before they lay eggs. Use on kittens over 8 wks of age. Each package contains 4 tubes.

Amazon.com Review 

Biting fleas are more than just a nuisance for your cat. Left unchecked, they can cause serious disorders such as flea allergy dermatitis, secondary skin infections, tapeworms, and even anemia. This topical flea treatment stops fleas before they become a problem. Providing a full month of protection, it begins working in minutes, killing 98-100% of the fleas on cats within 12 hours, and 99% of flea larvae within 20 minutes. Plus, since dead fleas can't lay eggs and dead larvae can't hatch, the flea's life cycle is halted. Any new fleas your cat encounters are killed within two hours--preventing re-infestation for as long as four weeks. In fact, Advantage does such a good job breaking the flea's life cycle, there's no need to treat your cat's environment. Applied before the start of flea season, it helps keep your cat from becoming infested in the first place. Used year-round, it prevents fleas from over-wintering in your home to feast on your cat the next season. Safe for kittens as young as eight weeks and as small as nine pounds, Advantage is also water-resistant. This package includes 4 pre-measured doses in easy-to-use applicator tubes.

Warnings
Hazards to Humans:
Causes eye irritation. Harmful if swallowed. Do not get in eyes or on clothing. Avoid contact with skin. Wash hands thoroughly with soap and warm water after handling. Keep out of reach of children. Do not contaminate feed or food.
Hazards to Domestic Animals:
For external use only. Do not use on kittens under eight weeks of age. As with any product, consult your veterinarian before using this product on debilitated, aged, pregnant or nursing animals. Individual sensitivities, while rare, may occur after using ANY pesticide product for pets. If signs persist, or become more severe, consult a veterinarian immediately. If your animal is on medication, consult your veterinarian before using this or any other product. For consumer questions call 1-800-255-6826. For medical emergencies call 1-877-258-2280.
First Aid:
If in eyes: Hold eyelids open and flush with plenty of water. Get medical attention if irritation persists.
If swallowed: Call a physician or Poison Control Center.
If on skin: Wash with plenty of soap and water.