Sun chlorella rejuv-a-wafers are a superfood supplement to give your dogs and cats added nutrition. They do not contain any artificial colors, flavors or preservatives for a purer taste. They are also gluten-free and have no sugar for animals on restricted diets. The 60 wafers in each box provide a 60-day supply for pets under 50 pounds and a 30-day supply for pets over 50 pounds.