It's time to upgrade your ice pack! Your cooler can be leak-free all summer with the Set of 4 Ice Packs. The ultra-slim, stackable design makes them easy to store between adventures without taking over the freezer. The plastic shell is made of 100% BPA-free food-grade HDPE, making these reusable ice packs safe and convenient for everyday use in your lunch box or bag. This long-lasting ice substitute is an earth-friendly alternative to fast-melting ice or lower-quality plastic ice packs.