Product details:

This is a 25-pound bag of striped sunflower seeds. Striped sunflower seeds have a thicker shell, much harder for House Sparrows and blackbirds to crack open. So if you’re inundated with species you’d rather not subsidize at your black oil sunflower, before you do anything else, try switching to striped sunflower. Sunflower in the shell can be offered in a wide variety of feeders, including trays, tube feeders, hoppers, and acrylic window feeders. Sunflower hearts and chips shouldn’t be offered in tube feeders where moisture can collect.