Screw Worm Aerosol is A Multi Purpose premise spray used to treat screwworm and ear ticks as well as flies, mosquitoes, and gnats. Product works for up to 4 weeks. Product can Also be Used On Wounds to Kill and Repel Flies and Fly Maggots. Product contains Permethrin - 0.50% Other Ingredients 99.50%. ONLY SHIPPABLE WITHIN LOWER 48 STATES IN USA.