Munchkin Click Lock Bite Proof Sippy Cup, Yellow/Blue (qty 2) – AMAZON – $3.50 FS w/ prime

linky
About the Product
• Set of 2 BPA-free Sippy cups with 9 ounce capacity for water, milk or juice
• Soft, bite proof spout – guaranteed
• No room for error – locks in place with an audible click
• Easy-to-clean, one-piece valve
• Top rack dishwasher-safe, 9 Plus months
• These cups are spill-proof, meaning that liquid is contained inside the sippy cup when dropped or flipped upside down. To activate, the child needs to bite on the spout while drinking. This is a feature of the sippy cup