Micro air vents help prevent nipple collapse. BPA free (Made without BPA). 1 0-3m: Slow flow. Micro Air Vents help to prevent or reduce nipple collapse and minimize air ingestion. Classic nipples come in slow, medium and fast flow to meet your baby's changing needs. ParentLink. Answers. Advice. Affirmation. www.evenflo.com. 1-800-233-5921 8:00 am - 5:00pm EST. See insert for instructions and warnings. Made in Mexico.