Color-Changing Technology for Instant Temperature Clarity: See your milk's temperature at a glance. Purple means too cold, white means too hot, and blue means just right for feeding. Strong Seal, No Leaks: Pre-sterilized, thickened milk bags with double-sealed seams and double zippers to protect milk. To seal, press with your fingertips until you hear a click. Large Capacity for Worry-Free Storage: Hold up to 7 oz of milk per bag, cutting down on bag usage and saving time to make life easier for busy moms. Dual Openings for Zero Contamination: Two separate openings for milk input and output prevent contamination. Unzip the seal to pour in milk, and cut the corner when it's time to feed. BPA-Free for Peace of Mind: eufy breast milk storage bags are made of BPA-free materials, safeguarding your baby's health.