This spill-proof sippy cup is made to withstand every adventure. A rubberized lid and smooth mouthpiece ensure comfortable and safe sipping, and bottle comes with a protective cover. Tested by toddlers, beloved by parents. Did you know all wide mouth lids are interchangeable? That's right, the Nalgene bottle grows with you, allowing you to switch a Grip-n-Gulp lid for an OTF lock-top or Wide Mouth loop top whenever your child is ready.