The Original MAC since 1900 MAC(M.A.C) is a counter irritant and absorbent solution for the relief of bone, bursal and tendon lameness in horses. Comes with application brush. Composition per Fluid Ounce: Mercuric Iodide(5.4grs.), Mercuric Chloride(2.7grs.), Mercurious Chloride(18grs.), Isopropyl Alcohol(2%), Potassium Iodide, Potassium Nitrate, Potassium Chloride, Oil Camphor, Oil Terpentine, Idodo-Terpentine. For External Use Only. Product is Poisonous. Keep Out of Reach of Children. Read all Directions and Warnings on bottle prior to use.