This mineral block contains the same nine minerals in the same concentration as the natural mineral deposits.Calcium -Needed for strong bones, proper muscle function. min. 18%Iron - Carries oxygen in the blood. Manganese - Required for metabolism of fats and sugars. Potassium - Needed for normal heart amd muscle activity. Zinc - Promotes a healthy immune system. Copper - Helps keep blood vessels flexible for good circulation and promotes healing. Magnesium - Activates enzymes for absorption and transportation of nutrients. Phosphorus - Releases energy from carbohydrates, fats, and proteins. Sodium - Aids protein absorption and maintains ionic strength of body fluids. Comes with bolt holder to put on cage.