Zodiac topicals offer an effective and economical solution to kill adult fleas, mosquitos & ticks and flea eggs laid on your pet, in an easy to use once a month treatment. Zodiac POWERSPOT Flea & Tick Control for Dogs contains a powerful, effective insecticide that kills adult fleas and ticks on contact and Precor, a long lasting Insect Growth Regulator which prevents flea eggs and larv' from maturing into adults, effectively breaking the flea life cycle. Contains a powerful, effective insecticide which kills adult fleas & ticks on contact Also kills Blacklegged Ticks (Deer Ticks) which may carry the organism that carries Lyme disease Kills flea eggs laid on your pet for 4 weeks Effective, easy to use and economical Spreads over complete body through natural motion of animal 4 Month Supply Available Sizes: For Dogs Under 30lbs (14 kg), For Dogs Over 30lbs (14kg)