The bottle bags are made of . They can hold a milk bottle. With hand straps and convenient straps with clips, can be used for hanging on bag or buggy or stroller. They can keep a made milk warm for hours. If you have any milk leaks, you can use quick wipe to clean them easily. Features -Color:Assorted Color -Material:Polyester -Size:26.00X7.00X2.00cm/10.22X2.75X0.79in - Individual milk bottle carrier, easy to carry, holds up to most baby bottles on the market. - The inner layer can effectively lock the temperature, and can keep the heat for about 3-4 hours. - Built with a handle on the side of the bag, can attach it to your baby stroller handle or portable around you. - A perfect helper to keep the milk fresh when go outing, no longer worrying about baby will hungry outside. - Can also hold your water bottle, it is great to drink warm water in such a cold weather. Package list: 4 x milk bottle storage pouches