A small, reusable design that is easy to clean. Internal ribs provide a ton of surface area for adult fruit flies. Twist the tube each week to keep track of how old the culture is (align the numbers with the logo). The lid allows for controlled sprinkling of flies and proper ventilation. ~ Wash with warm, soapy water between uses, removing any uneaten food, and removing fly pupae shells stuck on the internal ribs with a pipe cleaner.