Zodiac Spot On II with Smart Shield for Dogs Over 14kg provides flea control for up to 4 weeks. It also kills Blacklegged Ticks (Deer Ticks) which may carry the organism that carries Lyme disease. This topical treatment kills flea eggs laid on your pet to effectively break the flea life cycle. It spreads completely over your pet's body through the natural motion of the animal. The easy-to-use Smart Shield applicator tip parts hair for direct application to pet's skin. The applicator helps keep liquid off hands and will not drip after opening. Each package contains a 3 month supply.