This Pacific Baby handle and spout set is used to convert a Pacific Baby thermal baby bottle into a thermal sippy cup. It is compatible with the 4 ounce and 7 ounce 3-in-one bottles and the all-in-one bottle and will keep your child's drink warm or cold for up to 6 hours (4 ounce) or 10 hours (7 ounce) which is extremely useful when you are out and about. This environmentally friendly accessory increases the usability of the bottles and you don't have to buy more plastic drinks bottles as your child grows. The set fits snugly onto the top of the bottle and is leak proof.