Calcium and iodine deficiencies are common in many caged birds because these vital nutrients are lacking in standard diets. Living World Bird Iodine Block contains essential minerals missing in seed diets and helps prevent mineral deficiencies. The block has metal twist ties molded into the back so the block can easily be attached to any cage. Contains essential minerals missing in seed diets Fortified with calcium and phosphorus Helps keep beak trim Available Sizes: Small / Large