Short on space in your diaper bag? Of course you are because you have one zillion things to carry around. That’s what makes these bottles so smart. They squash down into easily packable discs the size of hockey pucks, making them easy to stuff into a bag without taking up that much room. The bottle’s wide base makes it harder to tip and spill, and the bottles transition to sippy cups as baby grows by replacing the nipple and adding handles. Their removable base and twist-off top make cleaning easy.