Lets little kids drink like big kids. The training cup b.box is the ideal way for kids to learn to drink from a cup. It mimics the flow of a big kids cup, by funneling liquids into the rim for easy free-flow drinking. The cup also features a unique water window in the lid so kids can learn to see water as they’re drinking and judge how much to tilt their cup. Interchangeable base and lid means you can switch between the spout, sippy cup and training lids as baby grows.