Calcium and iodine deficiencies are common in many caged birds because these vital nutrients are lacking in standard diets. Living World® Iodine Block contains essential minerals missing in seed diets and helps prevent mineral deficiencies. Fortified with calcium and phosphorous, Iodine Block is a complementary pet food that is beneficial for all caged birds. Iodine Block helps in the prevention of brittle bones (lack of calcium), enlarged thyroid in budgies (iodine deficiency), egg-binding (lack of calcium), and tremors. Size: Small Feeding Directions: Place Living World® Iodine Block in an easily accessible location in the cage. Firmly attach wire hanger to cage bars. Leave Iodine Block in cage until fully used. Replace when required.