The secret is the patented non-spill, easy-sip AVENT Magic Valve found only in the AVENT Magic Cup. While drinking, the valve flexes open for air to flow in, allowing a continuous flow of liquid out. That means less suction is needed, making drinking from the Magic Cup easy for babies and toddlers. So easy in fact, that you can introduce cup feeding, using the Magic Cup, months earlier than other non-spill cups. Unlike other non-spill cups, the Magic Cup even works with pulpy juices. When not in use, the Magic Valve closes so no messy spills occur. The cups are easy to assemble and take apart and are dishwasher safe.