The Heath Outdoor Products Woodpecker Stack'Ms Seed Cake is a 7-ounce cake that features black oil sunflower seeds, peanuts and white millet. Our Stack'Ms seed cakes are specially blended to help you attract several types of birds to the same feeder. Mix and match flavors to find the perfect combination for your yard. Simply stack Stack'Ms on your Stack'Ms feeder, where they will be easily accessible to birds but sheltered from the elements. Guaranteed fresh. Don't forget to buy the Stack'Ms feeder (S-6).