100% spill-proof, leak-proof, and break-proof guarantee. With the new twist 'n click cup feature, simply twist lid on cup until you hear and feel the lid click closed, then you'll know the cup is 100% leak-proof. Designed with a child development expert to easily grip and sip. Thin, tapered spout ideal for little mouths. Narrow waist at top allows for more control in sipping. Easy to drink from because lid and cup are always aligned. Easy to activate - liquid flows easily when child sips. No-roll square shaped bottom fits in most cup holders. Lid is interchangeable with all Playtex cups. All parts are dishwasher safe. 9oz, stage 3 for 12+ mos.