I’ve thrown away others since we used it. No leak at all! My son loves it! Only one thing, the cap is a little too tight, he can’t open by himself but as it doesn’t leak at all, l just leave the bottle open.
UBMOM straw cup includes Backflow Prevention Disk to prevent the liquid in the bottle being backflow by pressure / temperature difference (hot/cold drink), while the Smart Cap is easy opening and at the same time can also help preventing water leakage for moving. Also, UBMOM straw cup can be used as a feeding bottle by replacing the straw nipple with the bottle nipple.