Safe Material - Our water bottle tops for kids is made of food-grade silicone material, which is safe, BPA Free and dishwasher safe. It can be reused and not easily damaged, lasting for a long time. | Leak Proof Design- Silicone water bottle spouts can be squeezed into different size bottles and fit perfectly. With leak proof and no spill flow control valve design, the liquid will not splash any more. | Wide Adaptation - This water bottle spout fits most of standard size (28mm) mineral water bottles and beverage bottles in the market. Great for protecting your child's mouth and gum from the hard plastic bottle mouth. | Portable ＆ Convenient to Use - The baby spout adapter is portable to take, you can put it in your bag or pocket when going outside. There is one silicone ring beside the spout adapter, which is very convenient for your toddler to hold. | Can Be Written to Mark - There is a round silicone tag beside the spout adapter, you can write the name on it with dry erase marker(Not included). Marking can be removed by washing with mild dish soap and water.