1.【Good Expansion】This ice crystal box contains dry ice crystal particles, the particles are coarse, the expansion is good, the cold storage is strong, the large capacity and high energy storage are used for a long time to cool down and cycle. 2.【Thickening Material】Freezer Packs for Coolers shell consist of thickened PE material. Leak-proof, sturdy, doesn't take up a lot of space, and is easy to clean. 3.【Simple to Apply】Ice crystals expand as they absorb water and freeze, so don't overfill when adding water. After expansion, put it in the refrigerator for about 2-4 hours, and then take it out for lunch bags, etc. 4.【Cold Preservation】Cooler Ice Packs can be used as air-conditioning fan ice crystals, making cold air more frosty, super long cold storage, and can be used repeatedly. 5.【Multiple Occasions】Ice packs are widely used in various cooling scenarios such as food preservation, air conditioning fan cooling, incubator preservation, back milk preservation, fish preservation, and pet cooling.