The Super Sport Cups comes with a super strong flip-open, durable & bite resistant mouthpiece so your little one can flip it open again & again whenever they're thirsty. With a freeflow, there's no effort required for the water to flow so your little one will be getting as much liquid as they need without you having to worry about spills. Made from Triton your little one will be able to see through the bottle and see how much water they have left to drink!