For Optimum Control And To Minimize Developement Of Insect S Resistance To Pesticide Variable Methods Should Be Used. Tage Each Animal In The Herd With One Tag Per Ear. Apply Tags When Flies First Appear In Spring. Remove In Fall. Lasts 5 Months. Keep Out Of Reach Of Children. Follow All Safety Guidelines Completely. Effectively Prevents Horn Flies And Face Flies For Beef Cattle Non-Lactating Dairy Cattle And Calves. Continual Insect Exposure May Lead To Resistance. Use Other Methods Too. Pirimiphos-Methyl O-(2Diethlylamino-6-Methyl-4-Pyrimidinyl) Oo-Dimethyl Phosphorothioate: 20 Percent. Other Ingredients: 80 Percent.