From Tommee Tippee
Leak-proof: Smart two-piece valve stops spills (but can be removed for free-flow drinking)Bite-proof: Durable one-piece spout is gentle on little mouths but tough enough to withstand tiny teeth.Measurement markers: So you can clearly see how much they've had to drinkIntuitive design: Curved handles are perfectly sized for little hands to carry and take on their next adventureEasy to clean: All pieces are dishwasher safe, and BPA free