About this item EFFECTIVE - Contains active ingredient Novaluron, which is an Insect Growth Regulator. This new generation technology is 99.9% effective at breaking the fly life cycle to help eliminate the fly population in your barn. SAFE - Unlike other brands, our active ingredient is not an organophosphate, and is completely safe for horses. PALATABLE - Administer one serving of our alfalfa and wheat midd-based pellets to your horses daily with their feed. AFFORDABLE - MultiFly is just as effective as other brands, at a lower daily cost to you. MADE IN THE USA - All of our products are manufactured in our facility in Colorado, since 1946.