Easy Transition From Bottle to Cup: German made bite-proof silicone spout, soft as mom's breast, featuring a bigger air vent, easy to suck, gentle on teeth and gum. Localized thickening design for better support, prevents nipple sagging. Best choice for breastfeeding babies, making weaning off bottle easier No Spill Design: Thyseed best trainer starter sippy cup features a highly efficient non spill sealed design, inverting lid without leakage, prioritizing safety, providing parents with peace of mind, whether at home, at nighttime, at playdates, in the car, or on-the-go, the leak proof technology minimizes the chances of liquid accidents Easy to Clean: Dishwasher (top rack) and sterilizer safe.Recommended for ages 6m+