Mombella is providing free exchange service to every customer buying from mombella.com -If Broken: Please email us with the order number/problem description/photo if your bottle teats are broken by accidence. -If size problem: Please email us with the order number/baby age if the teat size is not fit your baby's age and feeding needs. We will provide the exclusive coupon to you to get the new one for use continually. A warm reminder that please match the teat with your baby's age when you place the order of the bottles. Any questions, please email us any time.