You, as a pet owner, can feel confident that Advantage (imidacloprid) Topical Solution works against fleas, fast. Advantage is the fastest topical solution, proven to stop fleas from biting in 3 - 5 minutes after application. • Advantage kills 98-100 percent of fleas within 12 hours of initial application. In addition, one convenient treatment lasts for up to one month. You don't need to use another flea control. • Advantage kills fleas before they lay eggs, so their life cycle is broken. And because it kills flea larvae within 20 minutes of contact, you don't need to use an insect growth regulator (IGR). Advantage also inhibits larval development in your pet's surroundings by more than 99 percent. • Once a month, the pre-measured dose is applied from an easy-to-use applicator tube. Advantage then spreads naturally on the surface of the pet's skin, with the help of movement by your cat or dog. In a matter of hours, the fleas are gone. It's as simple as that! • Advantage is water resistant and continues to work even when your pet gets wet. Advantage keeps killing fleas after shampooing, swimming or exposure to rain or sunlight. • Available in 4 dosage sizes for dogs: 10 lbs. and under, 11-20 lbs., 21-55 lbs., and 56-100 lbs. • Please specify 4 pack or 6 pack and dosage size. Please note: Advantage for Cats is sold separately. Please use item #JB2330142.