Zero Plastic… Zero Yuck: Crafted from safe 100% medical grade platinum silicone Simple: Constructed with firm silicone which is lightweight, dishwasher safe, and shatter-proof Leak-Resistant top: Directions - Tight-fitting straw top won’t pop off when the bottle is squeezed Directions - Please refer to directions for optimal use - Install straw so that the short section is on the outside of the top, Kink the top of the straw, Maintain the kink while gently pressing the top completely onto the cup. See full directions in packaging. Repurpose-able: Use without the lid for a training cup or the perfect snack-sized cup! Baby Grows...Bottle Evolves: The my-my straw cup is compatible with the my-my sippy lid The my-my straw cup is the ideal transition for your toddler when he or she is ready to move away from an infant bottle. It is a great compliment to our Kiki line of stainless infant, sippy, straw, and sport bottles!