Clinically shown reduces colic. 100% leak-proof. Expands to 10 oz for easier bottle preparation. BPA Free: Bisphenol-A free. Pre-Sterilized Disposable Liners keep air out for more comfortable feeding. Most like mother. Drop-Ins Pre-Sterilized Disposable Liners collapse as baby feeds for less air, less gas and less colic discomfort. Manufactured to Playtex quality specifications. Made in USA.